In digital music processing technology, quantization is the process of transforming performed musical notes, (which may have some imprecision due to expressive performance), to an underlying timing grid that eliminates this imprecision. The purpose of quantization in music processing is to provide a more beat-accurate timing of sounds.
The most difficult problem in quantization is determining which rhythmic fluctuations are imprecise (and should be removed by the quantization process) and which should be left alone.
Applying standard quantization onto your music does not always result into an improvement, especially if it's guitar music.
Listen to example below. Although the notes of the guitar riff are perfectly timed by the rigid quantization, it tends to feel robotic and programmed. The short length of the notes (1/32), doesn't help either.