By default, new projects are 32 bars long. You can move the project end point—for example, to remove unused bars at the end of the project.
Drag the end-of-project marker in the ruler to the left or right.
During playback, a project stops when it reaches the end-of-project marker. When recording, the end-of-project marker moves to accommodate the end of the recording (if recording extends past the current position of the marker).