Animate objects or skeletons by setting markers (keys) to indicate timing and position.
Keyframe animation lets you transform objects or skeletons over time by setting keyframes (also known as keys). For example, you can keyframe the joints and IK handles of a character’s arm to create an animation of its arm waving. You can set keyframes by selecting an object and selecting from the Key menu in the Animation menu set or pressing S on the keyboard.
Keys are markers that specify the property values of an object at a particular time and space. Setting keys is the process of creating the markers that specify timing and action in your animation. Animation is the process of creating and editing the properties of objects that change over time.
For a short video that explains the basics of keyframing animation, see the Keyframe Animation in the 1-Minute Startup Movies.
For information on how to create keyed animation, see Set Keys and Edit Keys.
Once you create an object you want to animate, you set keys that represent when the attributes of that object change during your animation.