You mix tracks. Mastering involves balancing those tracks for a CD. Of course this has changed somewhat with online singles. It also includes ordering the tracks, ensuring a tonal consistency between tracks (assuming that’s desired), and finally perhaps putting some tonal sheen in everything.

For example, mastering may involve making a perfectly fine track mix a little louder or softer so it flows well with another track. I use Ozone for mixing, and some mastering, but for mastering I use CD Architect to assemble the tracks and burn the CD.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.