The name of the best 3d puzzle game ever made. Included in Half Life: The Orange Box for Xbox 360, Portal has the gamer solve puzzles by using a 'portal gun' to shoot two portals at the environment: one for an entrance, and the other for an exit, and vice versa. All the while, an computer voice guides the user through each stage, with more ominous comments at each stage.
Guy 1: Dude, lets get on Halo 3.
Guy 2: Hell no. I'm playing through Portal again.
A tear in the space-time continuum that allows immediate transportation from one area to another. Some portals allow time travel as well. Some individuals are known to have the power to, in fact, create portals using mind powers.
Quick, we must get back to the time portal! It is closing!
I will get to the delicious cake behind the wall using a portal, and then laz0rz to kill the hungry polar bear.