Video rendering is the process of converting media into a form that a human can view. An example of rendering is the conversion of a data file into a sequence of image that is displayed on video display. Rendering systems may be able to work with the sender to adapt the media into other formats as the connection speed or the capabilities of the rendering device change.

A video compositor is a system or device that can take video inputs or graphic images and combine them into one composite video signal.

Spatial scalability is the ability of a image or video to reduce or vary the number of image components or data elements representing that that picture over a given area (spatial area) without significantly changing the quality or resolution of the image.

Temporal scalability is the ability of a streaming media program or moving picture file to reduce or vary the number image or data elements representing that media file for a particular time period (temporal segment) without significantly changing the quality or resolution of the media over time.

Loss concealment is a process that attempts to alter a signal or display in a way that reduces the effects of errors (such as the loss of data packets). An example of a loss concealment process is the insertion of a previous frame in a video sequence that has had a fame lost.

This figure shows that a video compositor can take two or more video inputs or graphic images and combine them into one composite video signal. This example shows a video compositor that takes a video format (news clip), text graphics (scene caption) and a graphic image (explosion picture) and combines them (renders) onto a single video display.