This cheat enables and disables (toggles) no clip mode. In noclip mode, you do not collide with walls, objects, etc, allowing you to fly through/to any part of the map.
The syntax for the noclip command is as follows:
Find below working examples of the noclip command.
If when you run this command you are not in noclip mode, this command will enable noclip mode. If you have already enabled noclip mode, running the above command will disable it (toggle it off).