Computer Fundamentals PDF

Computer Fundamentals Discussion LESSON 1: Evolution/History of Computer A computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data that provides output in a useful format. You may already know that you can use a compu...

Computer Fundamentals Discussion LESSON 1: Evolution/History of Computer A computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data that provides output in a useful format. You may already know that you can use a computer to type documents, send email, play games, and browse the Web. You can also use it to edit or create spreadsheets, presentations, and even videos. The word computer comes from the Latin word “compute”, which means, “to calculate”. Thereby, a computer is an electronic device that can perform arithmetic operations at high speed. Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. Nowadays, generation includes both hardware and software, which together make up an entire computer system. There are five computer generations known till date. Each generation has been discussed in detail along with their time period and characteristics. In the following table, approximate dates against each generation has been mentioned, which are normally accepted. First Generation Computer  The period of first generation was from 1946-1959. The computers of first generation used vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes, like electric bulbs, produced a lot of heat and the installations used to fuse frequently. Therefore, they were very expensive and only large organizations were able to afford it. In this generation, mainly batch processing operating system was used. Punch cards, paper tape, and magnetic tape was used as input and output devices. The computers in this generation used machine code as the programming language. Some The main features of the First computers of Generation are this generation were Vacuum tube technology ENIAC Unreliable EDVAC Supported machine language only Very costly UNIVAC Generated a lot of heat IBM-701 Slow input and output devices IBM-650 Huge size Need of AC Non-portable Consumed a lot of electricity Second Generation Computer  The Some computers period The main features of of this generation of Second Generation are were second Use of transistors IBM 1620 generation Reliable in comparison to first was from generation computers IBM 7094 1959-1965. Smaller size as compared to CDC 1604 first generation computers In this CDC 3600 Generated less heat as generation, compared to first generation UNIVAC transistors computers 1108 were used that were cheaper, consumed less Consumed less electricity as power, more compact in size, more reliable compared to first generation and faster than the first-generation machines computers Faster than first generation made of vacuum tubes. In this generation, computers magnetic cores were used as the primary Still very costly memory and magnetic tape and magnetic AC required disks as secondary storage devices. Supported machine and assembly languages In this generation, assembly language and high-level programming languages like FORTRAN, COBOL were used. The computers used batch processing and multiprogramming operating system. Third Generation Computer The period of third generation was from 1965-1971. The computers of third generation used Integrated Circuits (ICs) in place of transistors. A single IC has many transistors, resistors, and capacitors along with the associated circuitry. The IC was invented by Jack Kilby. This development made computers smaller in size, reliable, and efficient. In this generation remote processing, time- sharing, multiprogramming operating system were used. High-level languages (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used during this generation. The main features of third generation are Some computers of this generation were  IC used IBM-360 series More reliable in comparison to previous two generations Honeywell-6000 series Smaller size PDP (Personal Data Processor) Generated less heat Faster IBM-370/168 Lesser maintenance TDC-316 Costly AC required Consumed lesser electricity Supported high-level language SSI and MSI Technology was used Fourth Generation Computer The period of fourth generation was from 1971-1980. Computers of fourth generation used Very Large Scale Integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements with their associated circuits on a single chip made it possible to have microcomputers of fourth generation. The main features of fourth Some computers of this generation are generation were MSI and VLSI technology used DEC 10 Very cheap STAR 1000 Portable and reliable Fourth generation computers PDP 11 Use of PCs became more powerful, Very small size CRAY-1(Super Computer) Pipeline processing CRAY-X-MP (Super No AC required Computer) Concept of internet was introduced Great developments in the fields of networks Computers became easily available level languages like C, C++, DBASE etc., were used in this generation. compact, reliable, and Fifth Generation Computer affordable. As a result, it gave rise to Personal Computer (PC) revolution. In this generation, time sharing, real time networks, distributed operating system were used. All the high-  The period of fifth generation is 1980-till date. In the fifth generation, VLSI technology became ULSI (Ultra Large-Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components. This generation is based on parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch in computer science, which interprets the means and method of making computers think like human beings. All the high-level languages like C and C++, Java,.Net etc., are used in this generation. Some computer types AI includes The main features of fifth generation are of this generation are Robotics ULSI technology Desktop Neural Networks Development of true artificial intelligence Laptop Game Playing and Natural language processing NoteBook Development of expert Advancement in Parallel Processing UltraBook systems to make decisions Advancement in Superconductor ChromeBook in real-life situations technology Natural language More user-friendly interfaces with understanding and multimedia features generation Availability of very powerful and compact computers at cheaper rates The Future Computer Future computers promise to be even faster than today's computers and smaller than a deck of cards. Offer “smart” or artificial intelligence features like expert intelligence, neural network pattern recognition features, or natural language capabilities. LESSON 2: Types of Computers Since the advent of the first computer different types and sizes of computers are offering different services. Computers can be as big as occupying a large building and as small as a laptop or a microcontroller in mobile & embedded systems. The four basic types of computers are as under:  1. Supercomputer 2. Mainframe Computer 3. Minicomputer 4. Microcomputer Supercomputer The most powerful computers in terms of performance and data processing are the Supercomputers. These are specialized and task specific computers used by large organizations. These computers are used for research and exploration purposes, like NASA uses supercomputers for launching space shuttles, controlling them and for space exploration purpose. The supercomputers are very expensive and very large in size. It can be accommodated in large air-conditioned rooms; some super computers can span an entire building. Mainframe Computer Although Mainframes are not as powerful as supercomputers, but certainly they are quite expensive nonetheless, and many large firms & government organizations uses Mainframes to run their business operations. The Mainframe computers can be accommodated in large air-conditioned rooms because of its size. Super-computers are the fastest computers with large data storage capacity, Mainframes can also process & store large amount of data. Banks educational institutions & insurance companies use mainframe computers to store data about their customers, students & insurance policy holders.  Minicomputer Minicomputers are used by small businesses & firms. Minicomputers are also called as “Midrange Computers”. These are small machines and can be accommodated on a disk with not as processing and data storage capabilities as super-computers & Mainframes. These computers are not designed for a single user. Individual departments of a large company or organizations use Minicomputers for specific purposes. For example, a production department can use Mini-computers for monitoring certain production process. Microcomputer Desktop computers, laptops, personal digital assistant (PDA), tablets & smartphones are all types of microcomputers. The microcomputers are widely used & the fastest growing computers. These computers are the cheapest among the other three types of computers. The Micro-computers are specially designed for general usage like entertainment, education and work purposes. Well known manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba. Desktop computers, Gaming consoles, Sound & Navigation system of a car, Netbooks, Notebooks, PDA’s, Tablet PC’s, Smartphones, Calculators are all type of Microcomputers. LESSON 3: Advantages and Disadvantages of Computer Advantages of computer Disadvantages of Computer Multitasking Virus and Hacking Attacks Multitasking is one of the major advantage of Virus is a worm and hacking are simply an computer. Person can perform multiple tasks, unauthorized access over computer for some multiple operation, calculate numerical illicit purpose. Virus is being transferred from problems within few seconds. Computer can email attachment, viewing an infected website perform trillion of instructions per second. advertisement, through removable device like USB etc. once virus is transferred in host computer it can infect file, overwrite the file etc. Speed Now computer is not just a calculating device. Online Cyber Crime Now a day’s computer has very important role in human life. One of the main advantages of Online cyber-crime means computer and network may have used in order to commit computer is its incredible speed, which helps crime. Cyberstalking and Identity theft are the human to complete their task in few seconds. All the operations can be performed very fast just points which comes under online cyber-crimes. because of its speed elsewise it takes a long time to perform the task. Reduction in Employment Opportunity Mainly past generation was not used of the computer or they have the knowledge of Cost/ Stores huge amount of data computer they faced a big problem when It is a low-cost solution. Person can save huge computer came in field. As we have seen in data within a low budget. Centralized database banking sector senior bank employees faced of storing information is the major advantage this problem when computer came to the that can reduce cost. banking sector. Accuracy Above were the main disadvantage of computer, One of the root advantage of computer is that no IQ, Dependency, No feeling, Break down are can perform not only calculations but also with the basic disadvantages of computer. accuracy. Data Security Protecting digital data is known as data security. Computer provide security from destructive forces and from unwanted action from unauthorized users like cyberattack or access attack. Capabilities of Computer  Speed: computer operates on data and commands at incredibly fast speed. Storage: computer can store enormous amount of data and information in its memory. Reliability: computers made of modern technology rarely breakdown and when they do, they are easily repaired. Consistent: if you input the same data into the computer using the same program, it will give you the same result all the time. Communicate: people can connect with others by the use of computers. Computer System LESSON 4: Components of Computer System Computer System is a collection of entities that are designed to receive, process, manage and present information in a meaningful format. A computer comprises of some basic elements. These include hardware, software, peopleware. No computer can function in the absence of these elements. Apart from these elements, a computer system comprises of three basic components. These components are responsible for making computers actually function. Let’s take a look at them in detail. Elements of a Computer System There are three major elements that make up a computer system. They all interact with each other and perform the task at hand. HARDWARE SOFTWARE PEOPLEWARE Hardware These are all the physical parts of a computer system. They are the tangible computer equipment and devices, i.e. you can see and touch them. Hardware components are the electronic or mechanical instruments, that help the users interface with the software, and also display the result of the tasks being performed. However, most of a computer's hardware cannot be seen; in other words, it is not an external element of the computer, but rather an internal one, surrounded by the computer's casing (tower). A computer's hardware is comprised of many different parts, but perhaps the most important of these is the motherboard. Peripherals A computer cannot do everything by itself. It needs help. Other devices that work with a computer are called peripherals. These devices are outside of the Central Processing Unit (CPU) and are not essential to the computer itself. The mouse, speakers, microphone, headphones, and printer above are peripheral devices. Other examples of peripherals are shown in the picture on the left. Input Devices. These components help users enter data and commands into a computer system. Data can be in the form of numbers, words, actions, commands, etc. The main function of input devices is to direct commands and data into computers. Computers then use their CPU to process this data and produce output. Examples: Keyboard, mouse, touch screens, Scanner, barcode readers, Magnetic Ink Character Readers (MICR), Optical Character Readers (OCR), etc. Output Device: To translate and display the result of the data processing. After data is processed, results are sent to an output device in the form of hard or soft copy. Examples: Monitor, Printer, Headphones, Speaker, Webcam, Microphone, etc. LESSON 5: Elements of Computer System Storage Device: A storage device is a piece of computer hardware used for saving, carrying and pulling out data. It can keep and retain information short-term or long-term. It can be a device inside or outside a computer or server. It is any computing hardware that is used for storing, porting and extracting data files and objects. It can hold and store information both temporarily and permanently, and can be internal or external to a computer, server or any similar computing device. There are two different types of storage devices: Primary memory Secondary memory Primary memory includes ROM and RAM, and is located close to the CPU on the computer motherboard, enabling the CPU to read data from primary memory very quickly indeed. It is used to store data that the CPU needs imminently so that it does not have to wait for it to be delivered. Generally smaller in size, these are designed to hold data temporarily and are internal to the computer. They have the fastest data access speed, and include RAM and cache memory. There are two key types of primary memory: ROM, or read-only memory RAM, or random access memory Differences between RAM and ROM ROM: Non-volatile Fast to read Storage devices do not require power to remember the data stored. Mass storage devices. Usually used in small quantities. Cannot be written to quickly Used to store boot instructions or firmware Relatively expensive per megabyte stored compared to RAM Note: A loss of power does not affect their ability to retain data. RAM: Volatile storage is more often called "Main memory". Fast to read and write Requires a continuous supply of electricity to store/retain data. Used as system memory to store data (including program code) that the CPU needs to process imminently Relatively cheap per megabyte stored compared to ROM, but relatively expensive compared to secondary memory Note: A loss of power means that any data stored will be lost irretrievably. When you are using an application, such as a word processor, the data (the document you are working on) is stored in RAM (Random Access Memory). If you lose power without explicitly saving your work, you will likely lose data. Lesson 6: Application Software and System Software Software Software, commonly known as programs or apps. The software component refers to the instructions, data, and protocols, which helps the user to do a set of specific tasks. It helps the user interact with the computer system with the help of hardware. Software, as you can imagine, is the intangible aspect of the computer system.  Basically, there are two main categories of software, which are as follows,  Application Software  System Software Application Software This is designed and created for end users to perform a specific personal, business, scientific processing tasks and specialized assignment in order to output useful information. An example would be a word processing application used to compose letters or brochures, such as Microsoft Word. Other popular examples include: Adobe Photoshop, Corel Draw, and AutoCAD. A collection of application software is bundled in a System Software package that is commonly known as a software suite. A typical suite includes software for word processing, presentation, graphic design, and spreadsheet. Examples include Microsoft Office, OpenOffice, and iWork. Software is written in computer languages such as Visual Basic, C, and Java. Note: The software component is stored on optical media, disk drives and cloud storage spaces System Software The system software is a programs that take control of the PC on start-up, and then play a central role in everything that happens within a computer system by managing, maintaining, and controlling other software and devices inside the computer. System software is also designed for providing a platform for running application software, and it includes the following: Lesson 7: Operating and Utility System Operating systems Are essential collections of software that manage resources and provide common services for other software that runs "on top" of them. These specialized programmes allow the communication between software and hardware. The operating systems run all the other computer programmes, and even regulate the startup process of the computer. In a typical setup, the operating system is like the motherboard for software. It is the first thing that is installed, followed by applications and other software. Examples: Windows, Mac OS X, and Linux (Three popular operating systems for traditional computers) Android OS, iPhone OS, Windows Phone OS, and Firefox OS. (Popular mobile operating systems) Drivers A device driver is a computer program that operates or controls a particular type of device that is attached to a computer. Each device needs at least one corresponding device driver; because a computer typically has at minimum at least one input device and at least one output device, a computer typically needs more than one device driver. Examples: Printer, Video adapters, Network cards, Sound cards, etc. Utilities Utility software is system software designed to help analyze, configure, optimize or helps maintain and protect the computer system. Utility software focuses on how the computer (including the hardware, operating system, and application software) operates. Utility software is generally used by people with an advanced level of computer knowledge. Examples: Anti-virus software, backup software and disk tools. Peopleware The people interacting with the computer system are also an element of it. We also call this element as Liveware/humanware. They are the ultimate “users” of the computer systems. There are three types of people that interact with the system, namely  Programmers: Professionals who write the computer programs that allow users to interact with the computer. They must have technical knowledge of computers and computer languages. System Analyst: They mainly design data processing systems, and solve problems that arise in data processing End-Users: Also known as operators, they are the people who interact with the computer system. Computer and Data Security LESSON 8: Computer Threats Data security refers to the process of protecting data from unauthorized access and data corruption throughout its lifecycle. Data security includes data encryption, hashing, tokenization, and key management practices that protect data across all applications and platforms. Why Data Security? Organizations around the globe are investing heavily in information technology (IT) cyber security capabilities to protect their critical assets. Whether an enterprise needs to protect a brand, intellectual capital, and customer information or provide controls for critical infrastructure, the means for incident detection and response to protecting organizational interests have three common elements: people, processes, and technology. Threats to Database Security Threats to the database security increase daily with the advent of newer and modern ways of managing data related transactions. Through the use of exploits, these transactions are susceptible to threats from the following: The Internet: Today, the widely used internet has facilitated the dynamic growth and transmission of data. Internet banking platforms are convenient for Harbor Deck Banking Ltd customers, but this has expanded the bank's database coverage and opened it up to a spectrum of potential threats. As a result of this, the bank's data is under constant threats such as malware, viruses, and SQL injection attacks. Hackers: These are deliberate attacks by individuals using expert computer skills to illegally access a computer system. Their motives include theft, fraud, and organizational sabotage. If a hacker is successful, customers' personal information or account details can be stolen and exposed. Fraud: Individuals attempt to gain illegal access to data with the intention of making financial or personal gains from the information. If Harbor Deck Banking Ltd suffers a security breach, the data could be copied and sold. For example, fraudsters could use  customer data to create cloned banking cards to carry out unauthorized financial transactions. Human Negligence: There is hardly a technology-based system that completely lacks a human interface. Expertise is required to properly implement the necessary security controls and ensure security policies are enforced. What is Information Security? In this lesson, you'll learn about the basic principles of information security and the best practices for keeping confidential information in your organization where it belongs. Information Security Information security is the theory and practice of only allowing access to information to people in an organization who are authorized to see it. While this includes access to information contained on computers, the concept is much broader than computers, encompassing all records under the control of an organization. The concept originated with the U.S. Central Intelligence Agency as a way to make sure documents were safe from being altered or accessed by people who weren't supposed to be able to obtain them, especially classified information. There are a few basic principles when it comes to information security Confidentiality One of the first basic principles is confidentiality. This simply means that information is not available to people who aren't authorized to view it. For example, in many companies information on how much employees are paid is kept secret. If an employee accessed the payroll records and found how much a colleague was paid, it would be a violation of the principle of confidentiality. Integrity Integrity in the context of information security means that people can trust that the information in an organization hasn't been tampered with in some way. For example, the accounting department in a company needs to be sure that sales data, expense data, and so on are accurate so they can generate quarterly financial statements. If a company was found to be falsifying financial data, it could be in serious trouble. Availability Availability means that people who are authorized to view data can do so when they need access. Since so much information is contained in computer systems, this means that IT departments have to make sure their systems are as reliable as possible. In large enterprise organizations, mainframe computers, with their reliability and redundant components, have long been the gold standard for high availability systems. These machines can run for years without having to be taken down for maintenance.  Maintaining Information Security Even though every organization these days stores data on computers, information security does not strictly deal with them. Information security is primarily a management phenomenon. Good information security starts from the top and is reflected in good IT policy. Organizations can't expect to simply rely on the IT department to maintain security. Computer Security Controls In simple language, computer security is making sure information and computer components are usable but still protected from people and software that shouldn't access or change it. The protection comes from controls, or technical, physical, and procedural choices that limit access to the computer components. What Is a Computer Security Risk? A computer security risk is really anything on your computer that may damage or steal your data or allow someone else to access your computer, without your knowledge or consent. There are a lot of different things that can create a computer risk, including malware, a general term used to describe many types of bad software. We commonly think of computer viruses, but, there are several types of bad software that can create a computer security risk, including viruses, worms, ransomware, spyware, and Trojan horses. Let's look at these in more detail. Viruses, Worms, & Ransomware Viruses are malware that are attached to other files in your system and may be used to destroy your data. Viruses have many capabilities, but, unlike worms, they usually require human interaction to spread from system to system, even if the user is unaware they are spreading it. Worms are like viruses, but, they have the ability to spread themselves from computer to computer, all on their own. They know how to attach themselves to portable storage devices, like USB drives or removable hard drives, or to move through the network by automatically moving to connected machines. Ransomware is a relatively new term for malware that, when installed on your system, makes all of your files unreadable, holding your data hostage until you pay the hacker the ransom. Ransomware may be delivered by a virus or by a worm and there is no guarantee that, even if you pay the ransom, you'll get your data restored. Spyware & Trojan Horses Spyware is malware that steals your data and may be used to spy on you by using your webcam or microphone without your knowledge. Once spyware is installed, it may steal your sensitive data by recording the login information you use or looking for sensitive files on your computer, then sending that data back to an attacker. In recent months, hackers have been able to access the webcam and microphone of computers and use pictures, video, or audio recordings to blackmail their victims. Trojan Horses are a special kind of virus. Like the famed wooden horse used by the Greeks to infiltrate the walled city of Troy, Trojan horse viruses are used to deliver other types of malware by hiding them inside programs or files that look legitimate. Lesson 8: Types of Software Security When you work in information technology (IT), it's important to keep your computers safe from people who wish to do your organization harm, whether from the inside or outside. This means looking at everything from the security of physical machines to the safety of operating systems and hardware. Physical Security Whatever kind of computers you have, you might think that the biggest threats to your machines and information might come from outside the organization; however, the biggest threats could actually come from people physically accessing the machine rather than hackers coming over the Internet. That's why physical security, or controlling who gets access to a computer, is so important. A data center is vulnerable to people walking up to servers and changing settings, and rebooting or turning off machines. That's why most of them require some kind of credential and procedure for gaining entry into a locked server room, like having a system administrator scan a company I.D. card. The increasing use of mobile devices comes with a lot of physical security risks as well. Someone using a company-issued laptop or tablet might go to the restroom in a coffee shop only to come back and find that a machine with sensitive data has been stolen. In one real life incident, an agent for the United Kingdom's MI5 agency had a laptop stolen from a bar, while another former head of the MI5 had one stolen from an airport. Not only are security incidents like these embarrassing, but also have the potential for grave consequences. One defense is using mobile device management software, which can track the location of devices like laptops, smartphones, and tablets and perform a remote wipe if they're reported missing. This means that all the data will be erased, making these devices useless if they fall into the wrong hands. OS Security Modern operating systems are built with security in mind. One of the most important features is the use of permissions. Under a permissions control scheme, users are only allowed to modify files if they've been given prior approval. Permissions can be allocated to the whole system, or groups and individual users. For example, a user working on a physics project at a university might be allowed to change files on a physics department server as they pertain to that project, but not be allowed to change the operating system files. Password Security One of the major elements of security is authentication. This is proving that you are who you say you are. The most common way of doing this is through the usage of a user account: a username and password. There are two types of authentication Single-factor - using one method of authentication.  Multi-factor- using two or more methods of authentication concurrently. The common methods include things you know (passwords and PINs), things you have (special tokens or ID cards) and something you are (fingerprints and other biometrics.) For the scope of this lesson, we're going to focus on the most common type: What you know. Passwords should balance between easy to remember and not easy to guess, making it difficult to think of passwords sometimes. Using these recommendations may assist in creating secure passwords and making them easy to remember: Should be longer than 8 characters Not be dictionary words or common phrases Should contain different types of characters: letters (upper and lower cased), numbers and allowed symbols Not be special or personal to the person, such as the title of a favorite movie or a friend's birthday Never be shared with other users, except for the case of a shared account in a business One method of creating passwords now is the passphrase. In a passphrase, you take something that is more than one word or even a sentence and manipulate it to become a single password for your account. For example, someone familiar with music may use the 1812 Overture, the song so wellknown with its inclusion of cannons as percussion instruments. As a passphrase, it might become: 1812OvertureBOOM!!! On consideration of the suggested rules, this meets every one of them. The only concern would be if the user had the album on their desk, violating the fourth in it being personal to the user. Software Security When using a computer, one of the threats is the possibility of viruses. Antiviral software can help block viruses, but taking precautions is just as important. One easy solution is to not use an administrator account for daily access. Using an account with administrator access to a machine could allow hidden malware, software with harmful intent, to automatically install itself from seemingly safe locations. Any downloads should be done from reputable sites only. Google or other search engines supply excellent information in determining if a site is safe site or not, plus give alternatives in the download process. Email Security Email is an excellent way of communicating. Faster and cheaper than physical mail, it seems to have many advantages. Unfortunately, this means that potential attackers can use these advantages as well. Phishing is a method where a clone site masks itself as a real site to get information about a person. In email, this is often done by sending links to clone sites for banking or service sites where you may give personal information that can be stolen. The emails will commonly tell you that there is a problem with your account or that your service will be cut off or that you have to login to confirm something.