FREQUENCY

The measure of how often a periodic event occurs, such as a signal going through a complete cycle. Frequency is usually measured in hertz (Hz), with 1 Hz equaling 1 occurrence (cycle) per second. In the United States, household electricity is alternating current with a frequency of 60 Hz. Frequency is also measured in kilohertz (KHz, or 1,000 Hz), megahertz (MHz, or 1,000 KHz), gigahertz (GHz, or 1,000 MHz), or terahertz (THz, or 1,000 GHz).