Although the preferred method of rendering for multiple computers is using the Watch Folder feature, you can also use multiple computers and multiple copies of After Effects to render a composition across a network. You can use multiple computers to render only still-image sequences; you cannot use multiple computers to render a single movie.
When you render a still-image sequence with multiple computers, rendering in each copy of After Effects starts at approximately the same time. By specifying that each copy skip existing frames or frames in progress, multiple computers can render the project simultaneously, writing the still-image sequence to a single folder.
There is no limit to the number of computers that you can use for rendering; in general, the more computers, the faster the rendering. However, if too many computers are used across a busy network, network traffic may slow down the entire process. You can detect network slowdown by observing the time spent in the Compressing & Writing stage in the Current Render Details section of the Render Queue panel.