I was planning on using the Youtube Android Player API, when I noticed it needs a YouTube Data API (v3), API key: https://developers.google.com/youtube/android/player/register
The Youtube Data API handles most youtube's interaction, like getRating, upload video's, rate video's , get playlists etc, and sets a quota based on those actions: https://developers.google.com/youtube/v3/getting-started#quota & https://developers.google.com/youtube/v3/determine_quota_cost
None of these actions are video playback though, that's what the Android Player does. I also can't find anything about quotas on the Android Player API section.
So, my question is two-fold: Why does the player API need the Data API, and is there a quota on usage of the player API?