In Premiere Pro, you specify the settings for each sequence, trim your clips, and assemble clips in sequences.
Every Premiere Pro project can contain one or more sequences, and each sequence in a project can have settings different from the settings for the others. For example, one project can contain one sequence optimized for 30-fps widescreen DV assets, another for standard 24-fps DV assets, and still another for HDV footage.
You assemble and rearrange sequences in one or more Timeline panels, where their clips, transitions, and effects are represented graphically. You can open a particular sequence on a tab in a Timeline panel among other sequences, or keep it by itself in its own dedicated Timeline panel.
A sequence can consist of multiple video and audio tracks running parallel in a Timeline panel. Multiple tracks are used to superimpose or mix clips. A sequence must contain at least one video track and one audio track.
Sequences with audio tracks must also contain a master audio track, where the output of regular audio tracks is directed for mixing. Multiple audio tracks are used to mix audio. You can specify the type of audio channels supported by each audio track and decide how they are sent to a Master audio track. To achieve even greater control over the mixing process, you can create submix tracks.