Euler:
Pronounced "oiler" Euler is a common method for calculating 3d rotations. Is popular because it uses 3 values X, Y Z angles. Euler requires a "rotation order" and can experie nce gimbal problems, the worst resulting in Gimbal Lock when 2 axes align. this is why it's sometimes refered to as Gimbal, instead of Euler.
Quaternion:
Method of rotation that uses four values, xyz and t. XYZ are position values used to calculate a vector direction, and t is a roll value.
Gimbal:
Gimbal is the effect caused when Euler rotation axes break the usual 90 degree angle difference on a rotation manipulator. The extreme of this is gimbal lock when two axes align completely.
World/Local Coords:
Rotation manipulators usually default to world or local (object) modes to rotate objects or components (verts edge faces). In local or object mode the manipulator will rotate with the object or section. In "world" the rotate manipulator stays aligned to the xyz layout of the scene.


Manipulator:
The widgit/tool that appears to help us visually click and rotate/move/ modify an object or selction.
Key or Keyframe:
Setting a value and recording it on a time value (frame) in animation.
In between:
The space (in time) between animation keyframes. usually the computer will fill in the motion with a direct path or corresponding numerical value that fits between the value of the keyframes.
TCB:
Stands for Tension Continuity and Bias, values that affect the "ease in and out" between keyframes. Used for quaternion rotations that don't have animation curves.
Quaternion Pole:
A direction that sets the role value's up point for quaternions.
