The First Generation of Computers (1940s–1950s) was based on vacuum tubes as the main electronic component.
They used magnetic drums and magnetic tapes for memory and were programmed in machine language. These computers were very large, slow, and consumed high power, generating a lot of heat. Input/output devices included punched cards and paper tapes.
Examples include ENIAC, UNIVAC 1, IBM 650, IBM 701.
The Second Generation (1950s–1960s) used transistors instead of vacuum tubes, which made them smaller, faster, and more reliable. Memory was based on magnetic cores and magnetic tapes/disks, and programming was done in assembly language.
Input/output devices were similar to the first generation.
Notable examples include IBM 1401, IBM 7090/7094, UNIVAC 1107.
The Third Generation (1960s–1970s) marked the use of integrated circuits (ICs). They featured large magnetic core memory, magnetic tape/disk, and supported high-level programming languages such as FORTRAN, COBOL, BASIC, Pascal, and C. Computers became smaller, cheaper, and more efficient, with improved speed and reliability. Input/output devices included keyboard, monitor, printer, and magnetic tape.
Examples are IBM 360, IBM 370, PDP-11, UNIVAC 1108.
The Fourth Generation (1970s–present) saw the advent of microprocessors and VLSI (Very Large Scale Integration) technology. Semiconductor memory such as RAM and ROM was used. Programming was done in high-level languages like Python, C#, Java, JavaScript, Rust, and Kotlin, often mixing third- and fourth-generation languages. These computers were smaller, faster, cheaper, and more reliable than their predecessors. Input/output devices expanded to include keyboard, pointing devices, optical scanners, monitor, printer, and networking capabilities.
Examples include IBM PC, STAR 1000, Apple II, Macintosh.
The Fifth Generation (present and future) is based on Artificial Intelligence (AI) using ULSI (Ultra Large-Scale Integration) and parallel processing. They can process natural language, are portable, small in size, and have huge storage capacity. Power consumption is low, while speed, accuracy, and reliability are remarkable. Input/output devices include keyboard, mouse, touchscreen, pen, speech recognition, light scanner, and printer.
Examples include desktops, laptops, tablets, and smartphones.