Mixing is the technique of blending all of the individual tracks in a recording to create a version of the song that sounds as good as possible.
This is called "the mix”
Balancing the levels of the tracks that have been recorded
Fine-tuning the sound of each instrument or voice using equalization (EQ)
Panning” the tracks between speakers to create a stereo image
Adding reverb, compression, and other effects to enhance the original recording
Audio Post Production
Audio post-production is the process of adding, manipulating and processing sound after the production phase has completed. For video content, this will be after there is a “picture lock” – or at least after the first picture lock.. and before the film, TV show or advert is broadcast.
Mixing sometimes includes a bit of editing – choosing the best bits of every take of a song, and sometimes even building musical elements from scratch. Sometimes there is so much editing involved it forms a separate stage in between tracking and mixing.