# Terebi playback

Terebi plays local media, YouTube videos and resolved Miruro episodes. These terms distinguish a playback request from the state the player has actually reached.

## Language

**Playback transition**:
A requested change of media, playback state, position, or quality that may still be awaiting completion. Acceptance of a request does not mean playback has reached the requested state.

**Playback intent**:
The user's latest requested playing or paused state, which can differ from the state playback has acknowledged.

**Acknowledged position**:
The playback position confirmed by the player after any pending seek or restoration has completed. A seek target or slider preview is not an acknowledged position.

**Restoration**:
Resuming a video's saved position, or preserving position and playing or paused state while changing its quality.

**Media identity**:
The identity of the video being played, independent of its selected quality or extracted stream address. For a YouTube video, this is its canonical video webpage URL. For a Miruro episode, this is its opaque catalog media ID and episode number, independent of provider and expiring source URL.