Battery powered. I have a similar model, and it’s great if you have a small yard. A big yard would probably take two charges. Negatives include a lack of the sheer suction power of a gas mower. Some grass takes a couple of passes.
A positive, and it’s a big one, is the ability to start and stop it at the touch of a lever (and a dead-man switch). After years of either having to leave a running gas mower to pick up something, or re-start a hot mower (good exercise for your pulling arm), this was really nice.