Setting

Earth
At the beginning of the novel he is on a more futuristic version of earth today. (Possibly 2100) There are new types of technology, and due to the way they are speaking, example- Astronauts and Buggers, and talking about the galactic fleet,  They are further into space travel. 
Monitors
Desk computers

Space
-Ender is taken there for combat training on the buggers. It is where he kills his first bugger. At battle school he is either at the spaceship or the station. Laserguns and Jumpsuits are mentioned a few times which shows the furturistic technology in space. Sustainable life in space. Handprint locks. 

Child, training and encouraging their development in leadership. Unlike now.

Why does setting matter-
Imformation on what its about.
Genre
Mood