G-Shock is a brand of watches manufactured by Casio

Casio

is a multinational electronic devices manufacturing company founded in 1946, with its headquarters in Shibuya, Tokyo, Japan. Casio is best known for its electronic products, such as calculators, audio equipment, PDAs, cameras, musical instruments, and watches...

, known for its resistance to shocks (e.g. hard knocks and strong vibrations). They were, and continue to be, designed primarily for sports, military, and outdoor adventure oriented activity; for example, practically all G-Shocks have some kind of stopwatch

Stopwatch

A stopwatch is a handheld timepiece designed to measure the amount of time elapsed from a particular time when activated to when the piece is deactivated. A large digital version of a stopwatch designed for viewing at a distance, as in a sports stadium, is called a stopclock.The timing functions...

 feature, countdown timer, light and water resistance

Water Resistant mark

Water Resistant is a common mark stamped on the back of wrist watches to indicate how well a watch is sealed against the ingress of water. It is usually accompanied by an indication of the static test pressure that a sample of newly manufactured watches were exposed to in a leakage test...

. Recent models have become more luxury and design oriented as well as becoming very popular among youth.
The first G-Shock was the DW-5000C designed by an engineer working for Casio named Kikuo Ibe.