Clipping (or Peaking) – Another word for distorting. “Clipping” is usually used when a channel on a DAW or mixing board has too much volume being sent into it. In general, you want to give a channel enough headroom so that clipping doesn’t occur.
Distortion – The result of a sound source overloading an amplifier or sound processor. Basically, new frequencies are added where there were none before. This can be pleasing or very harsh. The nature of the distortion depends on the equipment that is being distorted.
Fuzz – A specific type of distortion that cuts the tops off of waveforms to produce a particular sound. Fuzz sounds exactly like its name – fuzzy. Mostly used with electric guitars.
Gain – This is a synonym for volume, though it’s often used as another word for distortion.
Overdrive (or Drive) – Usually refers to the distortion that occurs when an amplifier is overloaded. Commonly used to describe guitar amp distortion. Considered to be “creamier” than the harshness of digital distortion.
Saturation – Usually refers to the distortion that occurs when a piece of analog equipment is overloaded by a sound passing through it. Though overloading digital equipment tends to produce harsh sounds, saturation can make a sound “fat,” “round,” or “smooth.” Saturation is one of the most sought-after parts of analog equipment.