Stop watching the output of a particular program after using watch command?

From man watch:

By default, watch will run until interrupted.

The key words are "until interrupted", which basically can be interpreted as until (but not limited to) the following happening:

• The user (you) pressed CTRL+C in the terminal.
• The system restarted.
• The process was issued a kill request.

Press CRTL+C to stop the command