VP8 is a high definition video codec, included in the open source WebM project along with VP9. Google has been the company in charge of releasing all VP8 patents, so it is free and perfectly accessible to anyone who wants to use it and adapt it to their needs.
Its main competitor is the H.264 codec. The quality of both is quite similar, but H.264 wins slightly in video scenes where there is a lot of movement, since VP8 can have some problems and show somewhat pixelated scenes.
Both are excellent options for video playback, and companies usually choose to use VP8 due to its free and open source nature. The main problem comes when the encoder does not support it, since many of them still do not, unlike H.264.
To check if an application, device or video playback platform supports VP8, we must check, in its specifications, if it supports WebM.