The word computer was first used to describe someone who could perform calculations or computations

First, there a thing called the abacus. It had little beads on a pole. It isn't clear where the abacus was first invented, because they were used in India as well as east Asia. The Roman and Japanese versions are designed for base 10 calculations. Each rod has a decimal value: the first is ones; second tens; third hundreds; fourth thousands; and so on. The beads are separated by a wall thing, so there’s two on the top of the wall and five on the bottom. If one of the beads is pushed up, then that means it’s activated. Its math is a little like how you figure out roman numerals.

In 1822, a guy named Charles Babbage started working on a thing called the Difference Engine. It was capable of computing several sets of numbers and making hard copies of the results, but because of funding, he was never able to complete a full-scale functional version of this machine. In June of 1991, the London Science Museum made a second Difference engine and later finished it in about 2000.

Later, Charles Babbage proposed the Analytical Engine. The Analytical Engine had an Arithmetic Logic Unit (ALU), basic flow control, and an integrated memory. It was the first general-purpose computer.

The first programmable computer was called the Z1. It was made by a German named Konrad Zuse, in his parent’s living room, and it took him from 1936-38. It was considered the first modern computer, and the first functional computer.

The first electric programmable computer was called The Colossus, developed by a guy named Tommy Flowers. It was first used in 1943. It was created to help British code breakers read encrypted messages German messages.

The ABC (Atanasoff-Berry Computer) started being developed by John Vincent Atanasoff and graduate student Cliff Berry in 1937. It was the first digital computer. It was continued being developed by Iowa State College in 1942. It used vacuum tubes for digital computation including binary math and Boolean logic. It had no CPU (Central Processing Unit). Later, the ENIAC was invented by J. Presper Eckert and John Mauchly at the University of Pennsylvania. It was begun to be built in 1943, but didn’t get finished until about 1946. It took up about 1800 square feet and took about 18000 vacuum tubes, weighing in at 50 tons.

The first computer company was the Electronic Controls Company and was founded in 1949 by J. Presper Eckert and John Mauchly; the same individuals who helped create the ENIAC computer. The company was later renamed to EMCC or Eckert-Mauchly Computer Corporation and released a series of mainframe computers under the UNIVAC name.

The first stored program computer was British made and called EDSAC. The computer performed its first calculation on May 6, 1949 and was the computer that ran the first graphical computer game, also called “baby”.

In 1942, Konrad Zuse Began working on the Z4, which later became the first commercial computer, after being sold to a German guy named Eduard Steifel on July 12, 1950.

On April 7, 1953 IBM publicly came out with the 701, its first electric computer and first mass produced computer. Later IBM introduced their first personal computer called the IBM PC in 1981. The computer was codenamed and still sometimes referred to as the Acorn. It had an 8088 processor, 16 KB of memory, which was expandable to 256 and utilized MS-DOS.

MIT introduced the Whirlwind Machine on March 8, 1955, and was the first digital computer with magnetic core RAM and real-time graphics.