Computer Fundamentals Tutorial

Computer System

• A computer is an advanced electronic device that takes raw data as input, processes it, and produces output.
• It performs five basic functions:
  • Takes data as input
  • Stores data/instructions in memory
  • Processes data to produce useful information
  • Generates output
  • Controls all the above functions

Generations of Computers

• There are five generations of computers, each characterized by a significant change in technology:
  • First Generation (1946-1959): Vacuum tube technology, unreliable, expensive, and used machine language
  • Second Generation (1959-1965): Transistor technology, more reliable, smaller, and used assembly language
  • Third Generation (1965-1971): Integrated Circuit (IC) technology, smaller, more reliable, and used high-level languages
  • Fourth Generation (1971-1980): Very Large Scale Integrated (VLSI) circuit technology, smaller, more powerful, and used time-sharing, real-time networks, and distributed operating systems
  • Fifth Generation (1980-present):Ultra Large Scale Integration (ULSI) technology, parallel processing, artificial intelligence, and user-friendly interfaces

Classification of Computers

• Computers can be classified into five types based on speed and computing power:
  • Personal Computers (PCs): Single-user, moderately powerful, and used for general applications
  • Workstations: Single-user, more powerful, and used for engineering, desktop publishing, and software development
  • Minicomputers: Multi-user, capable of supporting hundreds of users, and used for business applications
  • Mainframes: Multi-user, very large, and used for large-scale business applications
  • Supercomputers: Extremely fast, and used for specialized applications such as weather forecasting, scientific simulations, and graphics

Basic Anatomy of a Computer System

• A computer system consists of three main parts:
  • Central Processing Unit (CPU): The brain of the computer, responsible for processing instructions
  • Input Devices: Used to enter data and instructions into the computer
  • Output Devices: Used to display or produce the output
• The CPU consists of two parts:
  • Arithmetic Logic Unit (ALU): Performs arithmetic and logical operations
  • Control Unit: Controls the flow of data and instructions

Components of a Computer System

• Hardware components:
  • Processor: The central processing unit
  • Main Memory: Random Access Memory (RAM) used to store data and programs
  • Secondary Memory: Used to store data and programs on a long-term basis
  • Input Devices: Used to enter data and instructions
  • Output Devices: Used to display or produce the output
• Software components: Programs and data stored in the computer### Hardware and Software
• Hardware and software are mutually dependent on each other and must work together to produce a useful output.
• Hardware without software is useless, and software cannot be utilized without supporting hardware.
• Different software applications can be loaded on a hardware to run different jobs.
• A software acts as an interface between the user and the hardware.

Types of Software

• There are two main types of software: System Software and Application Software.
• System Software:
  • A collection of programs designed to operate, control, and extend the processing capabilities of the computer.
  • Examples include Operating System, Compilers, Interpreter, Assemblers, etc.
  • Characteristics: close to the system, fast in speed, difficult to design, difficult to understand, less interactive, smaller in size, and difficult to manipulate.
• Application Software:
  • Designed to satisfy a particular need of a particular environment.
  • Examples include Payroll Software, Student Record Software, Inventory Management Software, Microsoft Office Suite Software, etc.
  • Characteristics: close to the user, easy to design, more interactive, slow in speed, generally written in high-level language, easy to understand, easy to manipulate and use, and bigger in size.

Operating System

• An operating system is a program that acts as an interface between the software and the computer hardware.
• It is an integrated set of specialized programs used to manage overall resources and operations of the computer.
• Objectives of an Operating System:
  • Make the computer system convenient to use in an efficient manner.
  • Hide the details of the hardware resources from the users.
  • Provide users a convenient interface to use the computer system.
  • Act as an intermediary between the hardware and its users.
  • Manage the resources of a computer system.
  • Keep track of who is using which resource, granting resource requests, and mediating conflicting requests.
• Characteristics of an Operating System:
  • Memory Management
  • Processor Management
  • Device Management
  • File Management
  • Security
  • Job Accounting
  • Control Over System Performance
  • Interaction with the Operators
  • Error-detecting Aids
  • Coordination Between Other Software and Users

Computer Network

• A computer network is a system in which multiple computers are connected to each other to share information and resources.
• Characteristics of a Computer Network:
  • Share resources from one computer to another.
  • Create files and store them in one computer, access those files from the other computer(s) connected over the network.
  • Connect a printer, scanner, or a fax machine to one computer within the network and let other computers of the network use the machines available over the network.
• Hardware requirements for a Computer Network:
  • Network Cables
  • Distributors
  • Routers
  • Internal Network Cards
  • External Network Cards

Network Topology

• The layout arrangement of the different devices in a network.
• Common examples include:
  • Bus Topology
  • Star Topology
  • Mesh Topology
  • Ring Topology
  • Tree Topology
  • Daisy Chain Topology

Types of Computer Networks

• Based on their size, there are three main types of computer networks:
  • Local Area Network (LAN):
    • A group of computers connected with each other in a small place.
    • Characteristics: secure, fast (speed can range from 100 to 1000 Mbps), and not limited to wire connection.
  • Metropolitan Area Network (MAN):
    • Covers a larger area by connecting LANs to a larger network of computers.
    • Characteristics: larger than LANs, smaller than WANs, and covers a city or town.
  • Wide Area Network (WAN):
    • Provides long-distance transmission of data.
    • Characteristics: larger than LAN and MAN, can cover a country, continent, or even a whole world.
    • Examples: Internet connection, mobile broadband connections such as 3G, 4G, etc.