Gray, or Grey, any color formed by blending black and white. Gray tones range from nearly white to nearly black. The many tiny dots of black and white in a halftone reproduction of a photograph produce gray tones.
Electronics, the branch of science and technology concerned with the nature, uses, and manufacture of devices in which electrons flow through a gas, vacuum, or semiconductor. Learn all about electronics.
Radar seems to have infinite uses: Police use it to clock your speed, NASA uses it to follow satellites, meteorologists use it to track storms and the military uses it to track the enemy ... Learn all about radar technology!