Silence ⌃⌫ – Logic Pro X keyboard command of the day

  Silence    ⌃⌫

Set the level of the selected audio to minus infinity – amplitude zero.

I am not sure of the difference (at least what it means to me) between Silence and Trim. Certainly with Trim a new audio file must be created when joining regions. 

Seems like a destructive ‘Remove Silence’ command.

The ‘Remove Silence’ command behaves a bit differently depending on where the audio has been selected. If you select audio in the Tracks window the ‘Remove Silence’ command will replace the region on the track with newly-created regions. If you are working in the Project Audio window you will be given the option of replacing the region on tracks where it is used, or simply creating regions that you can use for other purposes.

Trim or silence audio files in Logic Pro – Apple Support

You can use the Silence command to set all amplitude values to 0, rather than removing (with Cut, Delete, or Trim) all data from the selected area of an audio file. This function is generally used to silence unwanted background noise in quiet passages.

 Trim regions in the Logic Pro Audio Track Editor – Apple Support

You can trim an audio region in the Audio Track Editor to remove part of the beginning or end of the region.

 Uses for Remove Silence in Logic Pro – Apple Support

You can use Remove Silence for a variety of different situations.