The Interpolation submenu of the Animation menu (and the shortcut menu that appears when you Control-click a keyframe) contains the following methods that set the shape of curves between keyframes:
Constant: When applied to a keyframe or curve segment, this method holds the keyframe at its current value and then abruptly changes to the new value at the next keyframe.
Linear: When applied to a keyframe, this method creates a uniform distribution of values through the keyframe from its two adjacent keyframes. When applied to a segment, this method creates uniform distribution of values between points.
Bezier: This method lets you manipulate the keyframe curve manually by dragging the tangent handles. If multiple Bezier keyframes are selected, or Bezier interpolation is applied to the curve segment, the handles of all selected keyframes are modified.
Continuous: This method behaves like Bezier interpolation, but without access to the tangent handles (which are calculated automatically). The parameter begins to change gradually, reaching its maximum rate of acceleration at the midpoint, then tapers off slightly as it approaches the second keyframe. When applied to a keyframe, the segments before and after the keyframe are affected. When applied to a curve segment, the segment between the keyframes is affected.
Exponential: This method creates an exponential curve between the current keyframe and the next, changing the value slowly at first, then reaching its maximum rate of acceleration as it approaches the next keyframe.
Logarithmic: This method creates a logarithmic curve between the current keyframe and the next, changing the value rapidly at first, then slowing drastically as it approaches the next keyframe.
Ease In: This method has a reverse-inertia effect, so a value change slows coming into a keyframe. When applied to a curve segment, the value change eases into the segment. This option is available only when you Control-click a keyframe; it is not available in the Animation pop-up menu.
Ease Out: This method creates a typical inertia-like lag, so a value change begins more slowly coming out of a keyframe. When applied to a curve segment, the value change eases out of the segment. This option is available only when you Control-click a keyframe; it is not available in the Animation pop-up menu.
Ease Both: This method combines Ease In with Ease Out, applying both at once. This option is available only when you Control-click a keyframe; it is not available in the Animation pop-up menu.
