The primary way of rendering and exporting movies from After Effects is through the Render Queue panel.
Rendering is the creation of the frames of a movie from a composition. The rendering of a frame is the creation of a composited two-dimensional image from all of the layers, settings, and other information in a composition that make up the model for that image. The rendering of a movie is the frame-by-frame rendering of each of the frames that make up the movie.
Render and export a movie
1- Select the composition from which to make a movie in the Project panel, and add the composition to the render queue: