"Use gestures"

I began using a simple word-processing program for Mac called “Writer.” In its “Preferences” you can choose “Use gestures,” but I cannot understand what it means. Is there anyone who can tell me what it is for?

On an iPad, you can drag your fingers across the screen to perform certain functions. I don’t think your screen is tactile, but perhaps you can use these gestures on the mouse pad?

Thank you, Alexandrec.
I put two fingers on the mouse pad, and widened the distance between them. Suddenly the window of the program became extended into a full-screen mode.