The first electronic digital computers were developed in the 20thcentury (1940–1945). Originally, they were the size of a large room,consuming as much power as several hundred modern personalcomputers (PCs). In this era mechanical analog computers wereused for military applications.
Modern computers based on integrated circuits are millions to billionsof times more capable than the early machines, and occupy a fractionof the space. Simple computers are small enough to fit into mobiledevices, and mobile computers can be powered by small batteries.Personal computers in their various forms are icons of the InformationAge and are what most people think of as "computers". However, theembedded computers found in many devices from mp3 players tofighter aircraft and from toys to industrial robots are the mostnumerous.
The first use of the word "computer" was recordedin 1613, referring to a person who carried outcalculations and the word continued with the samemeaning until the middle of the 20th century. Fromthe end of the 19th century the word began to takeon its more familiar meaning, a machine that carriesout computations.
In 1837, Charles Babbage was the first to conceptualize anddesign a fully programmable mechanical computer, hisanalytical engine. Limited finances and Babbages inability toresist tinkering with the design meant that the device wasnever completed—nevertheless his son, Henry Babbage,completed a simplified version of the analytical enginescomputing unit (the mill) in 1888.
The Atanasoff–Berry Computer (ABC) was the worlds firstelectronic digital computer, albeit not programmable.Atanasoff is considered to be one of the fathers of thecomputer.
The first program-controlled computer was inventedby Konrad Zuse, who built the Z3, anelectromechanical computing machine, in 1941.
The first programmable electronic computer wasthe Colossus, built in 1943 by Tommy Flowers.