Computer

A computer is a machine that is designed to perform mathematical calculations. Most computers manipulate data in the form of binary code, which consists of 1s and 0s.

Charles Babbage's Analytical Engine.

The world's first computer was built by Charles Babbage in 1833, which he called the Analytical Engine. It was powered by steam and could perform basic arithmetic calculations with accuracy up to six decimal places. It also featured a 'bit bucket' in the back that collected discarded and malformed bits resulting from the calculations; this bucket had to be emptied on a weekly basis. Charles Babbage's wife Ada Augusta, whom operated the Analytical Engine, is considered to be the world's first computer programmer.

Prior to the advent of computing machines, the definition for computer was a human being who performed complex mathematical calculations.

References

http://www.msu.edu/course/lbs/126/lectures/history.html