Animate > Set Key

Inserts a key in the time line at the time where the current time indicator is positioned.

Animate > Set Key >

Opens the Set Key Options window.

Set Keys on

Specifies which attributes will have keys set on them.

All Manipulator Handles and Keyable Attributes: Sets a key for the current manipulator, and if there is none, then the current object. This is the default.
All Keyable Attributes: Sets keys on all attributes of the selected object(s).
All Manipulator Handles: Sets keys on attributes affected by the selected manipulator. For example, when using the Move Tool, keys will be set on the Translate X, Y, and Z attributes only.
Current Manipulator Handle: Sets keys on attributes affected by the selected manipulator handle. For example, when using the Move Tool’s X translation handle, keys will be set on the Translate X attribute only.

Set Keys at

Specifies on what time the keys are set.

Set IK/FK Keys: When keying an IK handle or joint chain, Set IK/FK Keys adds keys for all attributes of the handle and all joint of the chain. This lets you create smooth IK/FK animations. This option is available only when “All Keyable Attributes” is on. For more information, see Animate > IK/FK Keys > Set IK/FK Key and Animate > IK/FK Keys > Enable IK Solver.

Hierarchy

Specifies which objects in a parent-child hierarchy will have keys set on them.

Selected: Sets keys only on attributes of the selected object.
Below: Sets keys on attributes of the selected object and its child objects.

Channels

Specifies what channels will have keys set on them.

All Keyable: Sets keys on all the channels of the selected object.
From Channel Box: Sets keys on the selected channels of the selected object.

Control Points: Sets keys on the control points of the selected objects. Control points are NURBS CVs, polygonal vertices, or lattice points. Be aware that if Control Points is on and you key an object with many control points, for example, a complex NURBS surface, you’ll set a large number of keys. This slows Maya operation. If you also set Hierarchy to Below, you might slow Maya operation even more. Turn on these options only when necessary.

If you delete the construction history of an object with keyed CVs, the animation will no longer work correctly.
Shapes: If on, sets keys on the attributes of an object’s shape node and transform node. If off, keys will be set only on the attributes of the transform node.