The program temporarily stores on the hard drive the data from previous steps in editing the track. It is possible to go to any of the previous steps by clicking on Undo in the Edit menu. When there are many tracks in the project or if the track is very long, each editing step occupies a lot of hard drive space while the project is open. Is it possible to turn off permanently the program’s function to remember all previous steps?
No, but you can discard the Undo history. See: http://manual.audacityteam.org/man/undo_redo_and_history.html#history