Traditional animators had to draw every single frame by hand and develop animation techniques. Modern animation uses software to store reusable actions in a "talent pool" to speed up the process. When animation began, a single animator produced thousands of drawings using "straight ahead" animation. Later, animators developed "keyframe" animation where they draw key poses and the computer calculates in-between frames. Successful animation relies on techniques like anticipation, follow through, exaggeration, timing, balance, and squash and stretch.