Glitch is a term used to describe a genre of experimental electronic music that emerged in the mid to late 1990s. The glitch aesthetic is characterized by a deliberate use of glitch based sonic artifacts that would normally be viewed as unwanted disturbances reducing the overall sound quality and are thus usually to be avoided in audio recordings.
Sources of glitch sound material are usually malfunctioning or abused audio recording devices or digital technology, such as CD skipping, electric hum, digital or analog distortion, bit rate reduction, hardware noise, computer bugs, crashes, vinyl record hiss or scratches and system errors. In a Computer Music Journal article published in 2000, composer and writer Kim Cascone classifies glitch as a sub-genre of electronica, and used the term post-digital to describe the glitch aesthetic. Another term for Glitch is Clicks & Cuts (sometimes only Clicks) deriving from the Clicks & Cuts Series released by the Mille Plateaux music label, which played a leading role in the development of the genre.
Source: Wikipedia