fundamentals of computing.pdf

FUNDAMENTALS OF COMPUTING LESSON 1 AND 2 CHEATSHEET 1. 1822: Charles Babbage conceives the Difference Engine, a mechanical calculator. 2. 1837: Babbage designs the Analytical Engine, considered the first general-purpose computer. 3. 1936: Alan Tu...

FUNDAMENTALS OF COMPUTING LESSON 1 AND 2 CHEATSHEET 1. 1822: Charles Babbage conceives the Difference Engine, a mechanical calculator. 2. 1837: Babbage designs the Analytical Engine, considered the first general-purpose computer. 3. 1936: Alan Turing publishes his seminal paper on the Turing Machine, a theoretical model of computation. 4. 1943: The Colossus, an electronic computer used to break German codes during World War II, is built. 5. 1946: The ENIAC, the first general-purpose electronic digital computer, is unveiled. 6. 1951: The UNIVAC I, the first commercially available computer, is delivered. 7. 1957: The first transistorized computer, the IBM 608, is released. 8. 1960s: The development of integrated circuits (ICs) leads to smaller, more powerful computers. 9. 1971: The first microprocessor, the Intel 4004, is created. 10. 1975: The Altair 8800, one of the first personal computers, is introduced. 11. 1981: IBM releases the IBM PC, which becomes the standard for personal computers. 12. 1984: Apple introduces the Macintosh, a user-friendly computer with a graphical interface. 13. 1990s: The internet revolutionizes communication and information sharing. 14. 2000s: Mobile computing and smartphones become ubiquitous. 15. Present Day: Cloud computing, artificial intelligence, and quantum computing push the boundaries of computing. DEFINITION OF A COMPUTER Computer is a programmable machine. Computer is an electronic device that manipulates information, or data according to a list of instructions (program). Computer has the ability to store, retrieve, and process data. Computer is any device which aids humans in performing various kinds of computations or calculations. No matter which program a computer is using, the machine itself performs only four basic operations: Input: A computer accepts data that is provided by means of an input device, such as a keyboard. Processing: A computer performs operations on the data to transform it in some way. Output: A computer produces output on a device, such as a printer or a monitor, that shows the results of processing operations. Storage: A computer stores the results of processing operations for future use. USES OF COMPUTER The purpose of the computer is to transform data into information data means some kind of unorganized material that can be entered into the computer. What results from processing operations is information, i.e. data that has been made meaningful and useful. This capability to process data can be used in a variety of ways. People have come up with some very interesting uses. The importance of Computer Literacy Computers have touched every part of our lives: the way we work, the way we learn, the way we live, even the way we play. It almost is impossible to go through a single day without encountering a computer, a device dependent on a computer, information produced by a computer, or a word that was introduced or whose meaning has changed with the advent of computers. Because of the significance of computers in today’s world, it is important to be computer literate. Being computer literate means you have knowledge and understanding of computers and their uses. Principle Characteristic of Computer It responds to a specific set of instructions in a well-defined manner. It can execute a pre-recorded list of instructions. It can quickly store and retrieve large amounts of data. Computers have revolutionized nearly every aspect of our lives, becoming indispensable tools for communication, education, entertainment, and countless other applications. Their impact spans from personal use to global industries, transforming the way we work, learn, and interact with the world. Ubiquitous Applications Across Diverse Fields: Education: Computers have transformed education, offering online courses, interactive learning platforms, and access to vast digital libraries. Students can research topics, collaborate with peers, and access educational resources from anywhere in the world. Business: Computers are essential for managing business operations, from accounting and inventory control to marketing and customer relationship management. They enable efficient communication, data analysis, and online transactions, driving productivity and competitiveness. Healthcare: Computers play a vital role in healthcare, enabling medical imaging, patient record management, drug research, and telemedicine. They assist in diagnosis, treatment planning, and monitoring patient health, improving patient care and outcomes.  Science and Research: Computers are indispensable tools for scientists and researchers, enabling complex simulations, data analysis, and modeling. They facilitate collaboration, accelerate discoveries, and drive advancements in various fields, from astronomy to medicine. Government: Computers are integral to government operations, enabling efficient data management, citizen services, and policy development. They facilitate communication, information sharing, and the delivery of public services, contributing to good governance and transparency. Entertainment: Computers have revolutionized entertainment, providing access to movies, music, video games, and online streaming services. They enable interactive experiences, virtual reality, and creative content creation, enriching our leisure time. Transportation: Computers play a crucial role in transportation systems, from air traffic control and railway networks to navigation systems and autonomous vehicles. They enhance safety, efficiency, and connectivity, transforming the way we travel. Communication: Computers have revolutionized communication, enabling email, instant messaging, video conferencing, and social media. They connect people across the globe, facilitating collaboration, information sharing, and social interaction. ADVANTAGES OF USING COMPUTER Computers can do the same task repetitively with the same accuracy. Computers do not get tired or bored. Computers can take up routine tasks while releasing human resource for more intelligent functions. DISADVANTAGES OF USING COMPUTER Computers have no intelligence; they follow the instructions blindly without considering the outcome. Regular electric supply is necessary to make computers work, which could prove difficult everywhere especially in developing nations. Basic Terms Related to Computers The basic terms related to generations of computers are listed below. 1. Vacuum Tube: Vacuum tubes have the functionality of controlling the flow of electronics in a vacuum. Generally, it is used in switches, amplifiers, radios, televisions, etc. 2. Transistor: A transistor helps in controlling the flow of electricity in devices, it works as an amplifier or a switch.  3. Integrated Circuit (IC): Integrated circuits are silicon chips that contain their circuit elements like transistors, resistors, etc. 4. Microprocessors: Microprocessors are the components that contain the CPU and its circuits and are present in the Integrated Circuit. 5. Central Processing Unit (CPU): The CPU is called the brain of the computer. CPU performs processing and operations work. 6. Magnetic Drum: Magnetic Drum is like a cylinder that stores data and cylinder. 7. Magnetic Core: Magnetic cores are used to store information. These are arrays of small rings. 8. Machine Language: Machine Language is the language that a computer accepts (in the form of binary digits). It is also called low-level programming language. 9. Memory: Memory is used to store data, information, and program in a computer. 10. Artificial Intelligence: Artificial Intelligence deals with creating intelligent machines and behaviors. THE EARLIEST COMPUTER Originally, calculations were computed by humans, whose job title were computers. These human computers were typically engaged in the calculation of a mathematical expression. The calculations of this period were specialized and expensive, requiring years of training in mathematics. The first use of the word “computer” was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued to be used in that sense until the middle of the 20th century.  The earliest computers, depending on how you define "computer," can be traced back thousands of years. Here's a breakdown of some of the most notable early computing devices: 1. The Abacus (2700 BC): Often considered the first digital computer, the abacus was a simple counting tool used for addition and subtraction. It was invented in Mesopotamia and later adopted by civilizations in Egypt, Greece, and China. were a manual calculating device invented They were designed to simplify multiplication and division, and even extract square roots. How Napier's Bones Worked: The device consisted of a set of rods, typically made of bone, ivory, wood, or metal. Each rod represented a single digit (0-9) and contained a multiplication table for that digit, displayed in a grid format. known as the Arithmetic Machine, was the first mechanical calculator to be produced in quantity and actually used.  Charles Babbage is known as the Father of Computers for his pioneering work on the concept of a programmable mechanical computer in the 19th century. was intended to automate the calculation of polynomial functions, which were essential for scientific and engineering applications at the time. FIRST GENERATION COMPUTERS The technology behind the primary generation computers was a fragile glass device, which was called a vacuum tube. These computers were very heavy and really large. These weren’t very reliable and programming on them was a tedious task as they used low-level programming language and used no OS. First-generation computers were used for calculation, storage, and control purpose. They were too bulky and large that they needed a full room and consume a lot of electricity. Punch cards were used for improving the information for external storage. Magnetic card used. Machine and assembly language is developed. CHARACTERISTICS OF FIRST-GENERATION COMPUTERS Characteristics Components Main electronic component Vacuum tube. Programming language Machine language. Main memory Magnetic tapes and magnetic drums. Input/output devices Paper tape and punched cards. Speed and size Very slow and very large (often taking up an entire room). Examples of the first generation IBM 650, IBM 701, ENIAC, UNIVAC1, etc. SECOND GENERATION COMPUTERS Transistors were invented in Bell Labs. The use of transistors made it possible to perform powerfully and with due speed. It reduced the dimensions and price and thankfully the warmth too, which was generated by vacuum tubes. Central Processing Unit (CPU), memory, programming language, and input, and output units also came into the force within the second generation. Languages used for programming during this era: FORTRAN (1956), ALGOL (1958), and COBOL (1959). CHARACTERISTICS OF SECOND-GENERATION COMPUTERS Characteristics Components Main electronic component Transistor. Programming language Machine language and assembly language. Memory Magnetic core and magnetic tape/disk. Input/output devices Magnetic tape and punched cards. Smaller in size, had low power consumption, and generated Power and size less heat (in comparison with the first-generation computers). PDP-8, IBM1400 series, IBM 7090 and 7094, UNIVAC 1107, Examples of the second generation CDC 3600, etc. THIRD GENERATION COMPUTERS During the third generation, technology envisaged a shift from huge transistors to integrated circuits, also referred to as IC. Here a variety of transistors were placed on silicon chips, called semiconductors. The most feature of this era’s computer was speed and reliability. IC was made from silicon and also called silicon chips. CHARACTERISTICS OF THIRD-GENERATION COMPUTERS Characteristics Components Main electronic component Integrated circuits (ICs). Programming language High-level language. Memory Large magnetic core, magnetic tape/disk. Input/output devices Magnetic tape, monitor, keyboard, printer, etc. IBM 360, IBM 370, PDP-11, NCR 395, B6500, UNIVAC 1108, Examples of the third generation etc. FOURTH GENERATION COMPUTERS In 1971 First microprocessors were used, the large-scale of integration LSI circuits built on one chip called microprocessors. The advantage of this technology is that one microprocessor can contain all the circuits required to perform arithmetic, logic, and control functions on one chip. LSI placed thousands of transistors onto a single chip. CHARACTERISTICS OF FOURTH-GENERATION COMPUTERS Characteristics Components Very-large-scale integration (VLSI) and the Main electronic component microprocessor (VLSI has thousands of transistors on a single microchip). semiconductor memory (such as RAM, ROM, Memory etc.). pointing devices, optical scanning, keyboard, Input/output devices monitor, printer, etc. IBM PC, STAR 1000, APPLE II, Apple Macintosh, Examples of the fourth generation Alter 8800, etc. Fifth Generation Computers The technology behind the fifth generation of computers is AI. It allows computers to behave like humans. It is often seen in programs like voice recognition, area of medicine, and entertainment. Within the field of game playing also it’s shown remarkable performance where computers are capable of beating human competitors. CHARACTERISTICS OF FIFTH-GENERATION COMPUTERS Characteristics Components Based on artificial intelligence, uses the Ultra Large-Scale Integration (ULSI) technology Main and parallel processing method (ULSI has millions of transistors on a single microchip and electronic the Parallel processing method use two or more microprocessors to run tasks component simultaneously). Language Understand natural language (human language). Size Portable and small in size. Input/output Trackpad (or touchpad), touchscreen, pen, speech input (recognize voice/speech), light device scanner, printer, keyboard, monitor, mouse, etc. Example of the fifth Desktops, laptops, tablets, smartphones, etc. generation Phases of Computer Generations Generations of Computer Time-Period Evolving Hardware First Generation 1940s – 1950s Vacuum Tube Based Second Generation 1950s – 1960s Transistor Based Third Generation 1960s – 1970s Integrated Circuit Based Fourth Generation 1970s – Present Microprocessor Based Artificial Intelligence Fifth Generation Present – Future Based What are the 5 types of generation of computer? The five generations of computers are: 1. First Generation (1940s-1950s): Characterized by vacuum tubes and punched cards. Examples: ENIAC, UNIVAC. 2. Second Generation (1950s-1960s): Transistors replaced vacuum tubes, allowing smaller and more efficient computers. Introduction of high-level programming languages. Examples: IBM 1401, IBM 7094. 3. Third Generation (1960s-1970s): Integrated circuits (ICs) replaced transistors, leading to smaller and faster computers. Introduction of operating systems. Examples: IBM System/360, DEC PDP-11. 4. Fourth Generation (1970s-1980s): Microprocessors brought computing power to individual users. Introduction of personal computers. Examples: IBM PC, Apple Macintosh. 5. Fifth Generation (1980s-Present): Focus on parallel processing, artificial intelligence (AI), and natural language processing. Development of supercomputers and expert systems. Ongoing advancements in AI and machine learning. Examples: IBM Watson, Google’s DeepMind. What is Gen Z technology? Gen Z technology encompasses the digital tools and platforms that define the experiences of individuals born roughly between the mid-1990s and early 2010s. This generation is characterized by its seamless integration of smartphones, social media, online collaboration, and video content into daily life, shaping their communication, learning, and entertainment habits. 3. What is Artificial Intelligence? Artificial Intelligence (AI) is the simulation of human intelligence in machines. It involves programming computers to think, learn, and perform tasks that traditionally require human intelligence, such as problem-solving and decision-making. AI encompasses subfields like machine learning and natural language processing, with applications ranging from virtual assistants to autonomous vehicles. 4. What was the First Computer? The ENIAC (Electronic Numerical Integrator and Computer), completed in 1945, is widely regarded as the first electronic general-purpose computer. Who is Known as the Father of Computers? Charles Babbage is known as the Father of Computers for his pioneering work on the concept of a programmable mechanical computer in the 19th century. The skill of standing out online is needed more than ever in today's digital world. Whether to become a young marketer or grow one's brand, it is most important to learn digital marketing concepts. With our Digital Marketing Live Training Program, you can do all that, right in line with what any willing student needs. The course focuses on hands-on training in SEO, Social Media, and Content Marketing. Build the skills to make a difference in creating campaigns and driving accurate results. Set trends, not follow them. Enroll now and dominate the digital world! ELEMENTS OF THE COMPUTING PROCESS Computers consist of hardware, the physical parts of the computer and software, the programs that tell the computer 'what to do.' Processing data into information (the computing process) involves more elements than just hardware and software. All these elements must be organized so that each works smoothly and efficiently with the others. In the computing process, computers integrate the use of five key elements which are given as follows: Hardware Software Data People Procedures The computing process, in short, includes everything and everyone necessary for the computer to perform a useful task. The following sections show that ‘how each of these elements works in the process’. HARDWARE A computer’s hardware consists of electronic devices; that parts you can see and touch. The term “device” refers to any of hardware used by the computer, such as a keyboard, monitor, modem, mouse, etc. SOFTWARE Software – also called program – consists of organized sets of instructions for controlling the computer. Some program exists for the computer’s use, to help it manage its own tasks and devices. Other programs exist for the user, and enable the computer to perform tasks for you, such as creating documents. DATA Data consist of raw facts, which the computer can manipulate and process into information that is useful to people Computerized data is digital, meaning that it has been reduced to digitals, or numbers. The computer stores and reads all data as numbers. Although computers use data in digital form, they convert data into forms that people can understand, such as text, numeral sounds, and images. USER People are the computer’s operators, or users. Some types of computers can operate without much intervention from people, but personal computers are designed specifically for use by people. CHARACTERISTICS OF COMPUTERS Computers are fast. Computers are reliable. Computers are accurate Computers can store massive amount of information. Computers can move information very quickly from one place to another CLASSIFICATION OF COMPUTERS 1. Supercomputers 2. Mainframe computers 3. Minicomputers 4. Workstations 5. Microcomputers, or personal computers Supercomputers Supercomputer are the most powerful computers. They are used for problem requiring complex calculations. Because of their size and expense, supercomputers are relatively rare. Supercomputers are used by universities, government agencies, and large business. Mainframe computers Mainframe computers can support hundreds or thousands of users, handling massive amounts of input and output or storage. Mainframe computers are used in large organization where many users need to access to shared data and programs Mainframe are also used as e-commerce servers, handling transaction over the internet. Minicomputers ▪ Minicomputers are smaller than mainframes but larger than microcomputers. ▪ Minicomputers usually have multiple terminals ▪ Minicomputers may be used as network servers and Internet servers. Workstations Workstations are computers specifically designed and configured to meet power users' technical computing requirements, including high performance, data integrity, reliability, and manageability. Microcomputers A microcomputer is a complete computer on a small scale, designed for use by one person at a time. An antiquated term, a microcomputer is now primarily called a personal computer (PC), or a device based on a single-chip microprocessor. Common microcomputers include laptops and desktops. Main parts of computers The two main parts of computer are: 1. Hardware 2. Software TYPES OF HARDWARE Computer Hardware are broadly divided into four types: Input Devices: Hardware used to input data into computer system like keyboard, mouse Output Devices: Hardware used to output processed data from computer system like Monitor, printer Storage Devices: Hardware used to store the data like hard disk, Pen, Drive, CD System Unit: Hardware present in System Unit Like CPU, Motherboard, Graphics Card, Data Bus, System Cables, Ports etc. TYPES OF SOFTWARE Software are broadly divided into two types System Software: System software is any computer software which manages and controls computer hardware so that application software can perform a task. Operating systems, such as Microsoft Windows, Mac OS X or Linux, are prominent examples of system software Application Software: application software are programs that enable the end-user to perform specific, productive tasks, such as MS Word for word processing or Photoshop for image manipulation. Software System: A comprehensive set of interconnected programs that includes system software, middleware, and hardware interfaces to manage and control a larger environment. It supports broader operations, often in enterprise or complex setups. App Software: A program designed to perform specific tasks for users, like word processing or social media. It operates within a software system but focuses on serving the end user's direct needs. Key Difference: A software system is broader and more complex, while app software is task-specific and user-oriented. Hardware and software are fundamental components of a computer system, and they serve different roles in computing. Here’s a detailed comparison of the two: Hardware Definition: Hardware refers to the physical components of a computer system that you can touch and see. This includes all the tangible parts that make up the computer. Examples: Central Processing Unit (CPU): The brain of the computer that performs instructions and processes data. Motherboard: The main circuit board that houses the CPU, memory, and other components. Memory (RAM): Temporary storage used to hold data that is currently being processed. Storage Devices: Hard drives (HDDs), solid-state drives (SSDs), and optical drives that store data long-term. Input Devices: Keyboards, mice, scanners. Output Devices: Monitors, printers, speakers. Peripherals: External devices like USB drives, webcams, and external hard drives. Functions: Provides the physical infrastructure necessary for computing tasks. Executes instructions provided by software. Handles data input and output through various devices. Characteristics: Tangible: Can be physically touched and interacted with. Durable: Generally designed to last for many years. Fixed: Hardware components are physically installed and have limited flexibility. Software Definition: Software refers to the intangible set of instructions that tell the hardware how to perform specific tasks. It includes programs, applications, and operating systems. Examples: Operating Systems: Windows, macOS, Linux—these manage the hardware and provide a platform for other software. Applications: Microsoft Office, Adobe Photoshop, web browsers (e.g., Chrome, Firefox). Utilities: Antivirus software, file management tools, system maintenance programs. Programming Languages: Java, Python, C++—used to write software applications. Functions: Provides instructions for the hardware to execute specific tasks. Enables users to perform a wide range of activities, from word processing to gaming. Manages and coordinates hardware resources. Characteristics: Intangible: Cannot be physically touched; exists as code and data. Flexible: Can be updated, modified, or replaced easily. Dependent on Hardware: Requires hardware to operate but doesn’t interact with hardware directly. Key Differences 1. Nature: 1. Hardware: Physical, tangible components. 2. Software: Intangible, consisting of code and data. 2. Function: 1. Hardware: Performs actual tasks by executing physical processes. 2. Software: Provides instructions and manages how hardware performs tasks. 3. Modification: 1. Hardware: Changes are physical and often require replacing or upgrading components. 2. Software: Can be easily updated, modified, or reinstalled through digital means. 4. Dependency: 1. Hardware: Operates based on instructions from software. 2. Software: Requires hardware to execute and function. 5. Durability: 1. Hardware: Subject to wear and tear; physical components can break down. 2. Software: Subject to bugs and compatibility issues but not physically wear out. Interaction Software-Hardware Interaction: Software sends instructions to the hardware, which executes those instructions. For example, a word processor (software) sends data to the printer (hardware) to produce a hard copy of a document.  Hardware-Software Coordination: The operating system (software) manages the hardware resources and facilitates communication between different software applications and hardware components. In summary, hardware and software are interdependent; hardware provides the physical means to perform computations and tasks, while software directs how those tasks are executed. Together, they form the complete computing system. COMPONENTS OF COMPUTER SYSTEMS INPUT Input is the data entered in to a computer from the input devices like keyboard, mouse, scanner etc. Input data can be a character, word, image etc. When you enter information (input) in to your computer a signal is send to CPU (central processing unit). Any type of computer will always have two principal components: Hardware and Software. OUTPUT The process of producing the useful information for the user after processing input data is called output. After performing the calculations based on given instructions, the processed data is sent to the output device. Output device then translates the processed data in to a form (text, image, document etc.) that can understand to the user. System Unit The system unit is a case that contains electronic components of the computer used to process data The inside of the system unit on a desktop personal computer includes: The System Unit (often referred to as the computer case or tower) is the main part of a desktop computer. It houses the critical components necessary for a computer to function. Key Components Inside the System Unit: 1. Motherboard: The main circuit board that connects all components and peripherals. 2. Central Processing Unit (CPU): The brain of the computer, responsible for processing instructions. 3. Random Access Memory (RAM): Temporary storage for data and programs being used by the CPU. 4. Power Supply Unit (PSU): Converts electrical power from an outlet into usable power for the components. 5. Storage Drives: 1. Hard Drive (HDD) or Solid-State Drive (SSD) for storing the operating system, software, and files. 6. Graphics Processing Unit (GPU): Handles rendering of images, video, and animations (can be integrated or standalone). 7. Cooling System: Fans or liquid cooling to prevent overheating of internal components. 8. Expansion Cards: Additional cards such as sound cards or network cards, depending on the system. The system unit connects to external peripherals like monitors, keyboards, and mice, allowing the user to interact with the computer. The motherboard is the main circuit board of the system unit. PROCESSOR (CPU) The central processing unit (CPU) is the part of the computer which interprets and executes the commands from the computer hardware and software. CPUs used to be made up of discrete components and numerous small integrated circuits, which were combined together on one or more circuit board/s. However, due to modern manufacturing techniques, the term microprocessor is now used instead of CPU. This is a single integrated circuit (see Figure 1.2) which is at the heart of most PCs and is also found in many household devices and equipment where some control or monitoring is needed (e.g. the engine management system in a car). The CPU (Central Processing Unit) – which is also called microprocessor or processor – is in charge of processing data. How it will process data will depend on the program. The program can be a spreadsheet, a word processor or a game: for the CPU it makes no difference, since it doesn’t understand what the program is actually doing. It just follows the orders (called commands or instructions) contained inside the program. These orders could be to add two numbers or to send a piece of data to the video card, for example. When you double click on an icon to run a program, here is what happens: 1. The program, which is stored inside the hard disk drive, is transferred to the RAM memory. A program is a series of instructions to the CPU. 2. The CPU, using a circuit called memory controller, loads the program data from the RAM memory. 3. The data, now inside the CPU, is processed. 4. What happens next will depend on the program. The CPU could continue to load and executing the program or could do something with the processed data, like displaying something on the screen. Memory Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data. Stores three basic categories of items: 1. The operating system and other system software 2. Application programs 3. Data being processed and the resulting information The internal hard drive is the computer’s main memory; this is where the applications software, disk operating system and data files are stored. The main advantage of these memories is the fast data transfer/access times and their large capacity to store data Random access memory (RAM) Random access memory (RAM) is an internal chip where data is temporarily stored when running applications. This memory can be written to and read from. Since its contents are lost when power to the computer is turned off, it is often referred to as a ‘volatile’ or ‘temporary’ memory. RAM chips usually reside on a memory module and are inserted into memory slots. RAM: Temporary, volatile memory that stores data for active tasks and programs. Data is lost when the computer is turned off. ROM: Permanent, non-volatile memory that stores essential startup instructions. Data remains even when the computer is powered off. Key Difference: RAM is used for temporary data during operation, while ROM holds permanent data for booting and system functions. Example of Input-Processing-Memory-Output: 1. Input: You type a document using a keyboard (input device). 2. Processing: The CPU processes your keystrokes, interprets them, and prepares the text to be displayed. 3. Memory: The text is temporarily stored in RAM while you are working on the document. 4. Output: The text appears on your monitor (output device), allowing you to see what you typed. In this example, the cycle repeats every time you type a new character. Read only memory (ROM) Read only memory (ROM) is a memory used to store information that needs to be permanent. It is often used to contain, for example, configuration data for a computer system. These chips cannot be altered and can only be read from (hence their name). One of the main advantages is that the information stored on the ROM chip is not lost even when power is turned off to the computer. They are often referred to as ‘non-volatile’ memories. OPERATING SYSTEM An OS is a set of programs that controls how the hardware of a computer works… It is the means of communication between the user and the computer, deals with the loading and running of application programs and manages the transfer of data and files to and from the peripheral devices. Functions of Operating System The OS acts like a bridge between the applications software and the computer hardware. Users need applications software to carry out tasks, the software needs the operating system in order to communicate with the hardware Accepts data from input devices and transfers it to the computer’s memory.  Makes sure any output is sent to the correct output device. Manages the transfer of data between the computer’s memory and backing storage devices. Allocates memory space to programs and data. Loads applications software into memory and controls the running of them. Deals with any errors that occur when a program is being run and informs the user. Provides a human computer interface for the user Manages system security by restricting access to prevent unauthorized access to the system. TYPES OF COMPUTER Microcomputers Minicomputers Mainframe computers Supercomputers Microcomputers Microcomputers are small size and low-cost digital computers. These computers consist of central processing unit (CPU), input unit, output unit and storage unit. In microcomputers CPU is contained on a single semiconductor chip. Microcomputers are general purpose computers designed for individuals. The various examples of microcomputers are notebook computers or laptops, desktop computers or personal computers and netbook etc. The processing speed of microcomputer is less than mini and mainframe computer. Modern desktop computers, video game consoles, laptops, tablet PCs, and many types of handheld devices, including mobile phones, pocket calculators, and industrial embedded systems Desktop Computers: Apple iMac: Known for its all-in-one design and high-performance capabilities, suitable for both professional and personal use. Dell XPS: A series of high-performance desktops used for various applications, including gaming and professional work. Laptops: Apple MacBook Pro/Air: Popular for their sleek design and powerful performance, widely used in creative and business professions. HP Spectre: A high-end laptop known for its performance and portability. Tablets: Apple iPad: Offers versatile functionality with applications for productivity, entertainment, and education. Microsoft Surface: Provides a hybrid experience with a detachable keyboard and support for full Windows applications. Personal or desktop computer Desktop computer is a type of microcomputer designed for individuals. It consists of keyboard, monitor, mouse, power supply and system unit containing CPU, memory etc. They are used at home and business unit etc. It is difficult to carry desktop computers to different places. So, desktop computers are placed on a single location. Notebook computer Notebook computer is a portable personal computer. It contains all the features of a desktop computer. Notebook computer is also called as laptop. It is easy to carry from one place to other. Size of notebook computer is small compared to the size of desktop computer. They are used for various purposes including education, work etc. Modern notebook computers contain integrated web cam and microphone. We can recharge notebook computer by using a battery via an AC adapter. Netbook computer Netbook computer is a small, low cost and light weight computer. Its Weight is about 1kg. The hardware of netbook computer is less powerful than notebook computer. These computers are suitable for word processing and internet. The size of netbook computer is small compared to the size of notebook computer. Minicomputers Minicomputers are smaller than mainframe computers but larger than microcomputers. In 1960’s minicomputers were introduced. At that time mainframe computers are very expensive. Minicomputers are more powerful than microcomputers. The processing speed and storage capacity is higher than the microcomputer but lesser than mainframe computer.  Minicomputers are designed for multiple users. They can support hundreds of users simultaneously. These computers have large RAM and hard drive space. Minicomputers are more expensive than microcomputers but less expensive than mainframe computers. Scientific Research: Minicomputers were used in laboratories and research institutions for data analysis, simulations, and controlling experimental equipment. Industrial Control: They played a key role in managing industrial processes and automation, controlling machinery, and monitoring production lines. Business Applications: In business environments, minicomputers were used for tasks such as inventory management, payroll processing, and financial analysis. Educational Institutions: Universities and colleges used minicomputers for teaching and research, providing computing resources for students and faculty. Government Agencies: Minicomputers supported various government operations, including data processing and administrative functions. Minicomputers are also called as mid-range computers because the size of minicomputer falls between micro and mainframe computers. These computers are mostly used for research and business purpose. They are also used as network servers to manage large internet websites. Mainframe computers Mainframe is a very large and expensive computer. They could fill in an entire room. These computers are faster and more powerful than minicomputers but not as powerful as supercomputers. Mainframe computers are designed for multiple users. They can support hundreds of users simultaneously. Due to its high stability and reliability these computers work for decades without any interruption. Mainframe computers are mainly used by corporate and government organizations. These computers have large storage capacity. They are used for performing complex calculations. The first general purpose computer was a mainframe that was developed in the 1940s. Mainframe computers process millions of instructions in one second. Banking and Financial Services: Mainframes are heavily used in banking for handling vast numbers of transactions, including ATM transactions, electronic funds transfers, and account management. They e Transportation: Mainframes are employed in transportation sectors, such as airlines and railways, for managing reservations, scheduling, and ticketing systems. They handle large volumes of transactions and coordinate complex logistical operations. Ensure the accuracy  and reliability of financial operations, and manage large databases of customer information and transaction records. Supercomputers Supercomputers are the fastest and most powerful computers. The processing speed of supercomputers is high compared to other computers. The speed of supercomputer is measured in FLOPS (Floating Point Operations per Second). They can perform trillions of calculations per second. These computers are very expensive and large in size. Supercomputers are mainly used for scientific applications such as weather forecasting, aerodynamic research, animation graphics, biological research, molecular research and nuclear energy research. CDC 6600 is the first supercomputer that was developed in 1964 by Control Data Corporation (CDC).