GarageBand for Mac: What are regions?
Regions are the building blocks of a project. Each time you record an instrument, drag an Apple Loop to the Tracks area, or add a media file, a region containing the music from the recording, loop, or media file is created. Regions appear as rounded rectangles in the Tracks area.
There are several different types of regions, which are different colors:
Audio regions from audio recordings and audio Apple Loops are blue.
MIDI regions from software instrument recordings, software instrument Apple Loops, and imported MIDI files are green.
Imported audio files (without tempo information) are orange.
Drummer regions on Drummer tracks are yellow.
You can edit regions in the Tracks area in several ways. For example, you can: