Overhang means "a part of a structure or object that sticks out past the lower base or wall". That makes it pretty simple doesn't it?  Grab a photo today of something that is overhanging or sticking out.

This Las Vegas sign was hanging over the main strip in Vegas.  We would go under it every time we went up or down the strip.  It's a good thing it was there as it's just so easy to forget where you are.  Vegas is just so unassuming! (insert eye roll).