Computers actually developed from the “old time” counting machines. “Abacus” was one of the first counting machines that laid the foundation of the modern computers. Papyrus, which helped to record language and numbers, also contributed to the development of modern computers. It was as early as the 1640's mechanical calculators were manufactured for sale. Blaise Pascal invented the first commercial calculator, which was a hand powered adding machine. However, it was Charles Babbage, in 1837, who first conceptualized and designed a fully programmable mechanical computer that he called "The Analytical Engine". Charles Babbage computer provided the basics of the modern computers, and thus he is often considered as the “father of the computer”.

Konrad Zuse made a programmable electronic device, which was dubbed as Z1 Computer in 1936 – 1938. It was the First freely programmable computer. In the basement of the Physics building on the campus of Iowa State, John Vincent Atanasoff, assisted by Clifford (John) Berry, started working on a digital computer in 1936. They designed ABC Computer in 1942 to solve linear equations common in physics. The computer displayed some of the early features of later computers including electronic calculations.

Howard Hathaway Aiken, a US computer engineer, assisted by Grace Hopper, an American computer scientist and United States Navy officer, were pioneer in computing. They were the engineers behind IBM's Harvard Mark I computer in 1944. Harvard Mark I was the first large-scale automatic digital computer in the USA.

ENIAC 1 Computer, shortly known as ENIAC, short for Electronic Numerical Integrator And Computer, was the first large-scale, electronic, digital computer capable of being reprogrammed to solve a full range of computing problems. ENIAC was designed and built to calculate artillery firing tables for the U.S. Army's Ballistics Research Laboratory. ENIAC was conceived and designed by John Mauchly and J. Presper Eckert of the University of Pennsylvania in 1946.

The Manchester Small-Scale Experimental Machine (SSEM), nicknamed Baby, was the first stored-program computer to run a program, on June 21, 1948. It was developed by Frederic C. Williams and Tom Kilburn at the University of Manchester. The computer was built around a Williams tube, a particular type of cathode ray tube (CRT) which had been developed by Williams at the Telecommunications Research Establishment in July-November 1946, before he joined the University of Manchester in December 1946.

The UNIVAC I (UNIVersal Automatic Computer I) was the first commercial computer made in the United States in 1951. It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC. The first UNIVAC was delivered to the United States Census Bureau on March 31, 1951. It was used by CBS to predict the result of the 1952 presidential election.

IBM 701 EDPM Computer, also known as IBM 701 or Defense Calculator, was announced to the public on April 29, 1952. It was IBM’s first commercial scientific computer. The system used electrostatic storage, consisting of 72 Williams tubes with a capacity of 1024 bits each, giving a total memory of 2048 words of 36 bits each.

FORTRAN, the first successful high level programming language, was developed by John Backus & IBM in 1954. It was developed for scientific and engineering applications. It was general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing.

ERMA (Electronic Recording Machine-Accounting) and MICR (Magnetic ink character recognition) was a pioneering computer development project run at SRI (Stanford Research Institute) under contract to Bank of America, and General Electric in order to automate banking bookkeeping. The project, under the technical leadership of computer scientist Jerre Noe, ran from 1950 to 1955

The Integrated Circuit, also known as IC, microcircuit, microchip, silicon chip, or chip, a miniaturized electronic circuit, consisting mainly of semiconductor devices, as well as passive components, was developed by Jack Kilby & Robert Noyce in 1958.

Spacewar Computer Game, The first computer game was invented in 1962. The computer game was invented by Steve Russell at the Massachusetts Institute of Technology.

Mouse was invented by Douglas Engelbart of the Stanford Research Institute in 1963. Dr. Douglas C. Engelbart is an American inventor of Swedish and Norwegian descent. The device was nicknamed as “mouse” because the tail came out the end. Douglas Engelbart also developed the idea of window as a visual area, usually rectangular in shape, containing some kind of user interface, in 1964.

ARPANET (Advanced Research Projects Agency Network) was developed by DARPA (Defense Advanced Research Projects Agency) of the United States Department of Defense in 1969. ARPANET was the world's first operational packet switching network, and the predecessor of the global Internet.

Intel 1103 Computer Memory, The world's first available Dynamic RAM (DRAM) chip was invented by Dr. Robert Dennard at the IBM Thomas J. Watson Research Center in 1966 and patented in 1969-70.

Intel 4004 Computer Microprocessor, also known as Intel 4004, was the first microprocessor released by Intel Corp. in 1971. It was a 4-bit central processing unit (CPU), the world's first commercial single-chip microprocessor designed by Federico Faggin, the project leader and chip designer, and Ted Hoff (architecture) of Intel and Masatoshi Shima of Busicom (later of ZiLOG). The 4004 employed a 10μm silicon-gate PMOS technology and could execute approximately 60,000 instructions per second.

The "Floppy" Disk, a data storage device composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell was invented by Alan Shugart & IBM in 1971.

The Ethernet Computer Networking was invented by Robert Metcalfe & Xerox in 1973.

Scelbi & Mark-8 Altair & IBM 5100 Computers, the first consumer computers came in 1974/75. It was the evolution of a prototype called the SCAMP (Special Computer APL Machine Portable) that IBM demonstrated in 1973. Apple I, II & TRS-80 & Commodore Pet Computers, more consumer computers, came in 1976/77.

IBM announced the IBM 5110, the larger cousin of IBM 5100 in January 1978. However, IBM 5100 was withdrawn in March 1982, when the IBM PC - Home Computer was introduced in 1981. The IBM Personal Computer was the original version and progenitor of the IBM PC compatible hardware platform. It was IBM model number 5150, and was introduced on August 12, 1981. It was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida.

MS-DOS Computer Operating System, also MS-DOS (short for Microsoft Disk Operating System), began as QDOS (for Quick and Dirty Operating System), written by Tim Paterson for computer manufacturer Seattle Computer Products (SCP) in 1980-81. It was marketed by SCP as 86-DOS because it was designed to run on the Intel 8086 processor.

Apple Lisa Computer, The first home computer with a GUI, graphical user interface, came in 1983. It was first introduced in January 1983 (announced on January 19) at a cost of $9,995 US ($20,893 in 2007 dollars). It was one of the first commercial personal computers to have a GUI and a mouse. It used a Motorola 68000 CPU at a 5 MHz clock rate and had 512 KiB or 1 MiB RAM.

Apple Macintosh Computer, the more affordable home computer with a GUI, was released on January 24, 1984. Apple Macintosh was designed by the team engineers including George Crow, Joanna Hoffman, Burrell Smith, Andy Hertzfeld, Bill Atkinson, and Jerry Manock.

Microsoft waged a friendly war with Apple, introducing an operating system named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Microsoft Windows eventually came to dominate the world's personal computer market. The first version of Microsoft Windows was version 1.0. It lacked a degree of functionality and achieved little popularity. It did not provide a complete operating system; rather, it extended MS-DOS.

Microsoft Windows version 2.0 was released in November 1987, and was slightly more popular than its predecessor. Microsoft Windows version 3.0, released in 1990, was the first Microsoft Windows version to achieve broad commercial success, selling 2 million copies in the first six months. Microsoft released Windows NT based on a new kernel in July 1993. It was a professional OS and was the first Windows version to utilize preemptive multitasking. Microsoft released Windows 95 in August 1995. Microsoft Windows 98 was released in June 1998. Microsoft Windows 2000 came in February 2000. Microsoft Windows XP was released in 2001. Windows Server 2003 was introduced in April 2003, and finally Microsoft released Windows Vista On January 30, 2007.