In musical terms comp is short for accompaniment. Comping is the act of playing an accompanying musical part. In recording these definitions apply, but it has also come to mean the process whereby a part is played or sung several times on different tracks (or virtual tracks) of a recorder and then the best pieces of those performances are later “comped” or combined into one ideal performance. It may be something as simple as keeping the second verse from the first take, using the chorus from the second take, and the rest of the performance coming from the fifth take. Or, it could be as involved as taking the first syllable from the fifth word of the vocal and splicing it onto the beginning of the same word each time it comes up in the song. This has been going on since the early days of multitrack recording, but now that DAW‘s make it so easy to cut and past parts, the process is pretty much considered a standard recording technique, and it’s not uncommon to have dozens or even hundreds of small edits in a single vocal performance.