MHz is the shortened form of the word megahertz. It is important to understand the meaning of hertz to understand MHz. The term hertz is named for Heinrich Rudolf Hertz, who contributed significantly to the study of electromagnetism. Units within the International System of Units should always be capitalized if named after a person. When spelled out fully, the word should not be capitalized. That’s why the abbreviations are Hz or MHz but the terms are written out as hertz or megahertz.

Hertz can be used in the singular or the plural. It denotes a measure of frequency that counts the number of cycles completed in one second, with one hertz equaling one cycle per second. In fact, before the implementation of the term hertz, the measurement was actually called “cycles per second” or cps and MHz were called megacycles.

One MHz denotes one million hertz or one million cycles per second. It also equals 1000 kilohertz or KHz, which is often used to describe the measure of bandwidth. This is why your Internet connection will say 256 K or whatever the actual number is as measured in KHz.

Sound, light, radio frequency, and electromagnetic radiation can also be measured in hertz. Sound generally ranges up to tens of thousands of hertz, while physical vibrations are often measured in MHz. Radio frequencies are generally in much higher ranges and different types of light and rays such as gamma rays are measured in even higher ranges and are often described by other terms such as wavelengths.

MHz is commonly used to describe the measurement of speed for a CPU or central processing unit in a computer. Each function of the computer involves instructions that must be processed by the CPU. Each of those instructions involves a certain number of cycles per second. The number of instructions that can be completed in one second is called the clock speed.

MHz can also be used to measure the clock speed or number of cycles per second for other components such as video cards. In fact, it is a good idea to have a video card if you do any gaming, digital photography, or if you create your own graphics, so cycling large numbers of graphics doesn’t slow down your CPU. Clearly, a higher number of MHz means better speed as well as better performance for both types of components.