[[Dynamic range]] compression (DRC) or simply compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, thus reducing or compressing an audio signal's dynamic range. > by 1812, "pertaining to mechanical forces not in equilibrium, pertaining to force producing motion" (the opposite of static), from French dynamique introduced by German mathematician Gottfried Leibnitz (1646-1716) in 1691 from Greek dynamikos "powerful," from dynamis "power," from dynasthai "to be able, to have power, be strong enough," which is of unknown origin. The figurative sense of "active, potent, effective, energetic" is from 1856 (in Emerson). This relates to [[Statically typed]] and [[Dynamically typed]] programming languages. So dynamic is the opposite of static. Static on a television is something that is not moving (kind of). If something is dynamically typed, the type can change. It can move from one thing to another. In a [[Statically typed]] language, variables' types are _static_, meaning once you set a variable to a type, you cannot change it. If the variables' types are _dynamic_, you CAN change it. See [What is the difference between statically typed and dynamically typed languages?](https://stackoverflow.com/questions/1517582/what-is-the-difference-between-statically-typed-and-dynamically-typed-languages). Now, a dynamic range is a ratio of the difference between loud and quiet. Why did someone invent a compressor? Probably because someone was tired of moving the faders on a mixer.