Introduction to Computers

Introduction to Computer

• A computer is an electronic device for calculating, analyzing, and presenting data. It solves problems by applying prescribed instructions.
• A computer is made up of hardware (physical components) and software (programs and operating systems).
• It performs tasks such as processing data, storing, and retrieving information, communicating with other devices, running applications, and accessing the internet.
• Types of computers include desktops, laptops, tablets, smartphones, servers, and supercomputers.

Function of Computer

• Computers perform numerous functions and their use varies by user group.
• Initially, computers were used for scientific and military applications, primarily for calculations, especially in wartime.
• Today, computers are used for a vast array of tasks across numerous fields.
• General computer functions include data storage, calculations, analysis, and controlling devices.

Attributes of a Computer

• Speed: Computers process data quickly and accurately, often at nano or picosecond speeds.
• Access: Computers allow for quick access and retrieval of stored information.
• Security: Computers have built-in security measures to protect data from unauthorized access.
• Storage Space: Computer memory can store large amounts of information.
• Automation: Computers automate repetitive tasks.
• Communication: Computers enable easy and fast communication.
• Versatility: Computers can perform a multitude of tasks.
• User-Friendliness: The design of computers generally makes them easy to use.
• Scalability: Computers can be upgraded and expanded as needed.
• Cost-Effectiveness: Computers can reduce labor costs and increase productivity.
• Data processing: Computers efficiently handle large amounts of data.

Generations of Computers

• The first generation (1940-1945) used vacuum tubes.
• The second generation (late 1950s-early 1960s) introduced transistors.
• The third generation (late 1960s-1970s) used integrated circuits (IC).
• The fourth generation (1980s) featured very large-scale integration (VLSI).
• The fifth generation continues to use improvements.

Classification of Computers

• Computers are categorized in various ways based on size, processing power, purpose, and usage.
• The categorization includes supercomputers, mainframe computers, personal/microcomputers, and minicomputers.
• Attributes of each type (e.g size, portability, processing power) distinguish one from another.

Elements of a Computer

• Hardware: The physical parts of a computer, such as input devices (keyboard, mouse), output devices (monitor, printer), internal components (CPU, RAM), storage devices (hard drives, SSDs).
• Software: Programs and applications that tell the computer what to do. These include operating systems, application software, and utility software.
• Firmware: Small programs that keep the hardware running smoothly.
• Data: Raw information processed and stored by the computer.
• People: Users and operators interact with the computer and input data and instructions.
• Connectivity: Hardware and software that enable communication between various devices and networks.

Operating System

• An operating system (OS) is a set of programs that manages the computer's hardware and software resources.
• It controls various aspects like booting, memory management, data security, process management, and input/output functions.

Types of Operating Systems

• Single-user, single-tasking (e.g., MS-DOS)
• Single-user, multi-tasking (e.g., Windows, macOS)
• Multi-user (e.g., Unix, Linux)
• Real-time (for tasks with set deadlines)
• Mobile (e.g., Android, iOS)
• Server (e.g., Windows Server, Linux)

Computer Security and Threats

• Computer security protects computer systems, networks, and data from unauthorized access, use, disclosure, and disruption.
• Key aspects of computer security include confidentiality, integrity, and availability.
• Common threats include viruses, worms, trojans, malware, spyware, adware.
• Methods like firewalls, anti-virus software, encryption, and user awareness help mitigate threats.

Computer Storage

• Primary storage (RAM, ROM) holds data and instructions that the CPU directly accesses.
• Secondary storage (hard disks, SSDs) stores data permanently and is generally slower than primary storage.
• Tertiary storage (external hard drives) may be used to store larger amounts of data. Online cloud storage services are also widely used.

Computer Languages

• Computer languages allow humans to communicate with computers.
• Different types of languages exist, including high-level languages, low-level languages (machine code), assembly languages, and markup languages.
• Software translators like compilers, interpreters, and assemblers convert code between different language types making it easier for human interaction and processing by the computer.

Source Code and Object Programs

• Source code is the human-readable code written using a programming language.
• Object code is a machine-specific code produced from the source code that is ready for execution by the CPU.
• Source code needs to be translated to object code before execution.

The Word Transport

• Transport in computer science relates to moving data between different locations, devices, or networks.