Evolution of Computers: Generations Overview

First Generation of Computers

• Early computers were large and used vacuum tubes
• The Atanasoff-Berry Computer (ABC), Colossus, Electronic Numerical Integrator and Computer (ENIAC), Universal Automatic Computer I (UNIVAC I), Whirlwind, and the IBM 701 were first-generation computers
• Vacuum tubes were three-terminal devices consisting of a cathode, grid, and plate
• First-generation computers used vacuum tubes

Second Generation of Computers

• The use of transistors replaced vacuum tubes in the second generation of computers
• Transistors were smaller, cheaper, and more reliable
• Experiments done by the University of Manchester, resulted in the creation of one of the earliest transistor computers
• The first prototype machine was built in 1953 and the full-size version was commissioned in 1955
• The transistor is a three-terminal, solid-state electronic device that can control electric current or voltage

Third Generation of Computers

• The third generation of computers came as a result of the use of semiconductors
• Key improvements included speed and efficiency
• Users could interact with third-generation computers using keyboards and monitors
• Operating systems made it possible for computers to handle various applications simultaneously
• Computers became smaller and cheaper, making them available to a wider audience

Fourth Generation of Computers

• The rise of microprocessors led to the fourth generation of computers
• This generation saw thousands of integrated circuits being placed on single silicon chips
• The Intel P4004, released in 1969, was the world's first microprocessor

Computer Systems

• Computer systems are made of various components each with its own function
• The input unit receives user commands in the form of data and converts them into digital language format, sending it to the processing unit
• The processing unit processes the information it receives from the input unit
• The memory unit is responsible for storing data from input devices and the results from output devices
• The control unit manages the computer device functions and serves as the central component of the CPU, transferring commands to the ALU
• The arithmetic-logic unit is tasked with carrying out mathematical calculations and comparisons, as well as making decisions
• The output unit displays the process resulting from the input and processing units
• The output unit uses various devices including monitors

Operating Systems

• Operating systems (OS) control computer hardware and enable users to utilize the power of the system
• Operating systems are a collection of software programs and commands
• Key features of operating systems include abstraction, volatility, executable programs, expensive software, user-friendliness, and unpredictability

Common Operating Systems

• Windows, Mac OS, Android, and iOS are the most common operating systems in use today

Internet and the Web

• The web is interconnected and designed to allow easy access to various resources
• The web is accessible through hypertext or hypermedia links, which allow users to move smoothly from one page to another
• Tim Berners-Lee invented the World Wide Web (WWW) in 1989
• The first web page was launched on August 6, 1991
• The expansion of the web went global by the end of 1991
• The Internet is a vast network connecting millions of computers globally
• The Internet includes copper telephone wires, TV cables, and fiber optic cables
• The Internet allows for the seamless connection of computers across the globe

The Process of an Internet Connection

• When you enter a website the computer sends a request to the server where the website is stored
• Once the server receives the request, it retrieves the website and sends the data back to the computer.