A frame is a time measurement unit in C&C games. One frame is the smallest amount of time between separate events. In mapping, if multiple triggers are constructed to fire after the same number of frames passes, each trigger in that sequence will fire one frame later than the previous. A comparison to real time is mentioned in the rules, saying Frame time a spy shuts down power for (900 = 1 minute), inferring that every 15 frames, a second of in-game time passes.
Several ini flags use frames as a measurement of their effect's duration, for example, a weapon's, , an Ivan Bomb's delay ( ), and others.