Playlist is a static playlist, which does not grow while playing.
MIX is a dynamic playlist, which grows while playing based on a first song in the list. 2 new songs are added at the end of the song playback. Newly added songs are similar in Style to a "SEED" song, MIX was created by.

MIX can be created by Song, Album, Artist, Genre, or Folder.
1. When Mix is created by Song, HomeDJ will try to add songs similar to a selected song;
2. When Mix is created by Album, Artist, Genre, or folder, random song within selected Album, Artist, Genre, or Folder will be picked and MIX created based on that song.

For example you picked Bach pipe organ song. HomeDJ will try to add similar song, where major instrument is Pipe Organ and Genre is about Classical.

Or you picked Dance song, HomeDJ will try to add songs, which are similar to Dance, which might be Trance, House, Electronic songs.

You can limit MIX just to add songs, which are within picked song Genre. It is useful when you try to create a MIX of Children songs, or Classical songs, to make sure there is no Rap song will be added to where you do not want it to hear.