Computer Fundamentals, Web Technologies, and Enterprise Java Frameworks

Evolution and Generations of Computers

  • First Generation (1946–19591946\text{--}1959 / 1940–19561940\text{--}1956): Based on vacuum tubes. Key milestone: ENIAC (Electronic Numeric Integrator and Calculator), designed in 19461946 by J. Presper Eckert and John W. Mauchly at the University of Pennsylvania. Weighed 27 tons27\,\text{tons}, covered 167 m2167\,\text{m}^2, and performed addition/subtraction up to 1010 digits.

  • Second Generation (1959–19651959\text{--}1965): Driven by transistors (developed in 19471947 by William Shockley). Smaller, faster, and generated less heat, but remained costly.

  • Third Generation (1965–19711965\text{--}1971): Utilized Integrated Circuits (IC), invented in 19651965 by Jack Kilby. Enabled remote processing, time-sharing, and multiprogramming operating systems.

  • Fourth Generation (1971–19801971\text{--}1980): Powered by Very Large Scale Integrated (VLSI) circuits containing roughly 5,0005,000 transistors per microprocessor chip.

  • Fifth Generation (1980–onwards1980\text{--}\text{onwards}): Employs Ultra Large Scale Integration (ULSI) technology (10710^7 electronic components per chip), supporting parallel processing hardware and Artificial Intelligence (AI).


Five Generations of Computers Summary

Computer Hardware Architecture and Classification

  • System Components:

    • Input Devices: Keyboard, mouse, trackball, touchpad, scanner, webcam, microphone.

    • Output Devices: Printers (Impact e.g., dot-matrix vs. Non-Impact e.g., inkjet, laser, 3D), Displays (CRT, LCD, LED), Speakers, Headphones.

    • System Unit: Contains motherboard, Processor/CPU, and volatile memory (RAM).

    • Storage Media: Non-volatile media including Hard Disk Drives (HDD), Solid-State Drives (SSD), USB Flash Drives, Memory Cards, Cloud Storage, and Optical Discs (CD holding 650×106–1×109 characters650 \times 10^6\text{--}1 \times 10^9\,\text{characters}, DVD holding 17×109 characters17 \times 10^9\,\text{characters}, Blu-ray holding 100×109 characters100 \times 10^9\,\text{characters} / 46 hours46\,\text{hours} of video).

  • Computer Classifications:

    • Personal Computers (PC), Workstations, Minicomputers (10–100s10\text{--}100\text{s} of concurrent users), Mainframes (100s–1000s100\text{s}\text{--}1000\text{s} of users), and Supercomputers (e.g., NASA Pleiades with 245,536245,536 CPU cores and 935 TB935\,\text{TB} memory).

  • Current Trends: Internet of Things (IoT) & Smart Home Technology, Augmented/Virtual Reality (AR/VR), Machine Learning/AI, Automation, Big Data (e.g., WAZE), Physical-Digital Integration, and On-Demand Services.

HTML5 and Web Technologies Fundamentals

  • Web Technologies: Systems through which computers/devices communicate and deliver web content using markup languages.

  • Basic Structure:

    • <!DOCTYPE html>: Declares HTML5 standards rendering mode.

    • <html>: Root element containing <head> and <body>.

    • <head>: Encloses metadata, CSS style sheets, and document <title>.

    • <body>: Holds visible page content.

    • Syntax validation can be performed via the World Wide Web Consortium (W3C) Validation Service (validator.w3.org).


HTML5 Basic Structure Elements

  • Essential HTML Elements:

    • Headings: <h1> (largest/most significant) down to <h6> (smallest).

    • Hyperlinks: Created with `<a href=