A scrolling playing field allows the player to control an object in a large contiguous area. Early examples of this method include Taito's 1974 vertical-scrolling racing video game Speed Race, Sega's 1976 forward-scrolling racing games Moto-Cross (Fonz), Road Race, and Super Bug.
Parallax scrolling, which was first featured in Moon Patrol, involves several semi-transparent layers, which scroll on top of each other at varying rates in order to give an early pseudo-3D illusion of depth. Belt scroll is a method used in side-scrolling beat 'em up games with downward camera angle where players can move up and down.
A previously much used alternative to video game scrolling was the flip-screen method. In these non-scrolling games the player's character/vehicle would exit a screen by moving off one of the edges. The picture would then abruptly "flip" to the next screen, hence the name for the technique.
Source: Wikipedia, "Scrolling", available under the CC-BY-SA License.