Vocabulary — Key Terms

Definitions for the terminology across the ten core skills, grouped by topic area (After Effects 2025+).

Foundations & Animation

Composition — A container with its own frame size, frame rate and duration where layers are stacked and animated; name your first comp Main.
Transform properties — Anchor Point, Position, Scale, Rotation and Opacity — the five core animatable attributes of every layer.
Keyframe — A marker recording a property's value at a point in time; two or more let After Effects interpolate the motion between them.
Easy Ease — A one-click (F9) softening of a keyframe's velocity so motion accelerates in and decelerates out.
Graph Editor — A view that shows animation as editable curves; the Value graph plots the value, the Speed graph plots the rate of change.
Spatial vs. temporal interpolation — Spatial = the shape of a layer's motion path through space; temporal = the timing/velocity of the motion between keyframes.

Source Text — A text layer's content, available as an animatable property (hold keyframes to swap words, or drive it with an expression).
Text Animator — A property group on a text layer that, with a Range Selector, animates its characters (position, scale, opacity, etc.).
Range Selector — The Start/End/Offset controls that decide which characters an animator affects; animating Offset staggers motion across a word.
Animation Preset — A saved effect+keyframe combo (.ffx) applied from Effects & Presets, including the built-in text presets.

Mask — A path drawn on a layer that limits where the layer is visible.
Mask mode — How multiple masks on one layer combine — Add, Subtract, Intersect, Difference.
Mask Path (keyframed) — Animating a mask's shape/position over time — the basis of wipe-on reveals and shape morphs.
Feather / Expansion — Softening a mask's edge (feather) and growing/shrinking it (expansion).

Lumetri Color — The main color effect: Basic Correction, Creative (looks/LUTs), Curves, Color Wheels, HSL Secondary and Vignette.
Adjustment layer — An invisible layer whose effects apply to everything beneath it — grade or affect many layers at once.
White balance — Neutralizing color casts with Temperature and Tint so whites read as white.
HSL Secondary — Isolating a range of Hue/Saturation/Luminance to adjust one color without affecting the rest.
LUT — A look-up table that maps input colors to output colors — technical (color-space) or creative (stylized).
Vignette — A gradual darkening toward the edges to draw the eye inward.

Blend mode — Math-based rules for how a layer combines with those below (Screen/Add drop blacks; Multiply drops whites).
Pre-comp — A composition nested inside another so a group of layers behaves as one editable unit.
Keylight — The primary green/blue-screen keying effect.
Spill suppression — Removing green/blue light that bounces onto a keyed subject's edges.
Light wrap — Wrapping background light around a subject's edges so it sits in the new plate.
Contact shadow — A fabricated shadow that grounds a composited subject to a surface.

Alpha matte — A matte that uses the matte layer's transparency (shape/text outline) to define what shows through.
Luma matte — A matte that uses the matte layer's brightness — bright shows, dark hides.
Track matte — Assigning one layer as the matte for another (2023+: linked to any layer via the Track Matte column).
Set Matte effect — Uses another layer's channel as a matte without stacking adjacency — good for reusing one matte on many layers.

3D layer — A layer with its 3D switch on, gaining Z position and three-axis rotation for use with cameras and lights.
Two-node camera — A camera with a position and a separate point of interest it aims at.
Warp Stabilizer — An effect that analyzes and smooths shaky footage.
3D Camera Tracker — Solves a virtual 3D camera from 2D footage so inserted elements move with the shot.
Planar tracking (Mocha) — Tracking flat surfaces (planes) for screen replacement, corner-pin and roto.
Match-moving — Attaching graphics/3D so they lock convincingly to a moving live-action scene.

Roto Brush 2 — A Sensei-powered semi-automatic rotoscoping tool that isolates a moving subject after a few strokes.
Selection propagation — Roto Brush spreading your subject selection across frames.
Refine Edge — Capturing fine/soft edges (hair, motion blur) for a cleaner cut-out.
Freeze the matte — Committing/caching the roto result so it stops recalculating.
Expression — A JavaScript snippet on a property that calculates its value automatically instead of (or on top of) keyframes.
Pick-whip — Dragging to link one property to another, which writes the expression for you.
wiggle() / loopOut() — Built-in expressions for smooth random motion and for repeating keyframes (cycle/pingpong/continue).