In your selected video content you can change it’s:
- Audio language
- Subtitles language
- Video quality (why change video quality read more following this link https://palidziba.go3.lv/en/article/internet-consumption/
In order to do it please click on settings icon visible at bottom right side of the screen and select what you want. 
Example how to use settings in browser
Example how to use settings in mobile devices