# What is Hertz in physics?

In the field of physics, the Hertz (often denoted by the symbol ‘Hz’) can be defined as the derived unit of frequency. As per the International System of Units (often abbreviated to SI), one Hertz is equal to one cycle per second. The SI unit of frequency is named after the German physicist Heinrich Rudolf Hertz, who was the first person to arrive at some conclusive proof of the existence of electromagnetic radiation and electromagnetic waves. It is important to note that frequencies are often expressed in multiples of Hertz, such as kilohertz (denoted by kHz), megahertz (denoted by MHz), and gigahertz (denoted by GHz). The SI base unit of the Hertz is second-1 (or s-1). Note that the Hertz is an SI derived unit.