Separate recordings of multiple sound sources are made which are then used to create a single recording. Multiple takes of a single part (such as lead vocal) can be edited and compiled into one amazing recording.
The goal of mixing is to bring out the best in your multi-track recording by adjusting levels, panning, compression, EQ and time-based audio effects (chorus, reverb, delay). The process of blending all the individual tracks and turning them into a song.
Mastering is the final stage of audio production—the process of putting the finishing touches on a song by enhancing the overall sound.