Media content can be composed of a single period or multiple consecutive media content periods.

Periods describe a part of the content with a start time and duration. Each of those periods contains media components, such as video components with different view angles, or audio components for different languages or with different types of information.

The MPD can contain multiple Period elements in case of discontinuities, for example, when the configuration or number of available presentations in the Dolby AC-4 bitstream changes.