Audio mastering is a process that helps in enhancing your audio file after mixing. It is the final process of the audio production, where the song is polished and then prepared for distribution.
This process involves various steps, such as removing the flaws, adjusting the even volume, Separating instruments, removing the distortions, balancing stereo width, removing unwanted frequencies, and more.
Mastering professionals have a great understanding of the process, which they have gained from years of practice and experience. These experts examine the audio carefully to see if there are any flaws and then fix them to make them playable.