A composition is the framework for a movie. A typical composition includes multiple layers that represent components such as video and audio footage items, animated text and vector graphics, still images, and lights. You add a footage item to a composition by creating a layer for which the footage item is the source. You then arrange layers within a composition in space and time, and composite using transparency features to determine which parts of underlying layers show through the layers stacked on top of them. You render a composition to create a final output movie.

Simple projects may include only one composition; complex projects may include hundreds of compositions to organize large amounts of footage or many effects.

In some places in the After Effects user interface, composition is abbreviated as comp.

Use the Composition panel to preview a composition and modify its contents manually. The Composition panel contains the composition frame and a pasteboard area outside of the frame that you can use to move layers into and out of the composition frame. Only the area inside the composition frame is previewed and rendered. The offstage extents of layers—the portions not in the composition frame—are shown as rectangular outlines.

Each composition has an entry in the Project panel. Double-click a composition’s entry in the Project panel to open the composition in its own Timeline panel.

Use the Flowchart panel to see the structure of a complex composition.

Timeline button 

Click this button at the bottom of the Composition panel to activate the Timeline panel for the current composition.

Press the backslash (\) key to switch activation between the Composition panel and Timeline panel for the current composition.

Comp button 

Click this button at the upper-right of the Timeline panel to activate the Composition panel for the current composition.

Flowchart button 

Click this button at the bottom of the Composition panel to activate the Flowchart panel for the current composition.

When working with a complex project, you may find it easiest to organize the project by nesting compositions—putting one or more compositions into another composition. You can create a composition from any number of layers by precomposing them. If you are finished making changes to some layers of your composition, you can precompose those layers and then pre-render the precomposition, replacing it with a rendered movie.