The aria-label should be used to provide a text alternative to an element that has no visible text on the screen.
aria-label is an attribute defined in the WAI-ARIA(opens in a new tab) specification. This specification extends native HTML, allowing you to change the way an HTML element is «translated» into the accessibility tree.
This page demonstrates the new HTML5 video element, its media API, and the media events. Play, pause, and seek in the entire video, change the volume, mute, change the playback rate (including going into negative values).