This is an intro to the Dope Sheet. Although it can be brought up in any view, the Dope Sheet is commonly found in the Animation view [CTRL+LEFT].
This view plays a key role in editing animations. From my observations and uses of it, the primary functions of the view include:
- Deleting Keyframes [X]
- Moving Keyframes [G]
This tool can be worked with in conjunction with the Graph Editor for complete control of animations.