Distortion is a sound effect that adds noise to a sound source. Distortion can sound warm, fuzzy, or dirty depending on the type of distortion we use. A classic use is on electric guitar. There are many types of distortion. Traditional distortion is clipping, or overexerting the system, forcing the sound system to add noise. Modern distortion effects often emulate physical modules such as guitar amplifiers.
Distortion effects vary widely in their parameters, but almost all include a wet/dry mix. Dry is the original signal, wet is the effected signal. Amplitude and frequency are common parameters as well. Amplitude impacts the overall effect of the distortion. Frequency impacts the color of the distortion.