Once you have entered a series of drawings and exposures, you can create cycles out of them in several ways. This can be useful for example if you want to make or use a looping character's walking animation, referred to as a walk cycle.
When you create cycle, each instance of each cycled drawing is linked to the same drawing file. This means that if you change a drawing for the first instance of the cycle, it will update for every other instance of the cycle.
NOTE You can also copy and paste drawings and keyframes into cycles—see Pasting Cycles.