Frequency

The number of cycles through which an alternating current passes per second; in the U.S. the standard for electricity generation is 60 cycles per second (60 Hertz).

The number of times an ad is delivered to the same browser in a single sessions or time period.

For a periodic function, the number of cycles or events per unit time. 2. The number of cycles occurring per second of an electrical or electromagnetic wave; a number representing a specific point in the electromagnetic spectrum. [47CFR]