Measured in hertz (cycles per second), rate of repetition of changes / waves. The term frequency is also used for range (band) on the radio frequency spectrum, such as 800 MHz, 900 MHz or 1900 MHz.

Buying and selling large quantities of stocks in split seconds, and making pennies per share. High-frequency trading (HFT) is performed entirely by computer algorithms that look for and take advantage ...

(1) A group of frequencies in the electromagnetic spectrum that are assigned by regulatory agencies for a particular purpose. Also called a "frequency band." See frequency bands, spectrum, satellite ...