Top-roping is also a
rock climbing term. It means that a route is set up with a secured rope instead of having a
lead climber pull the rope up with him/her. The person
belaying would be doing it from the ground and not at the top of the
cliff.
I used to go top-roping as a teenager with my family. It only works if you can get to the top of the rock face without climbing. It feels safer than having a lead climber, but it all depends on how well the rope is set up. Make sure that the person knows his or her knots.