Frequency has the unit of "per second", but we use a special unit for this: hertz (Hz). Like any unit, we can add prefixes in front of it to make alternatives:
e.g. 1 kilohertz = 1 kHz = 1,000 Hz
You will no doubt be using a computer that has a speed of many mega-hertz, or even giga-hertz!
Historical note: hertz is named after the German physicist, Heinrich Hertz (d. 1967)