This refers to the color depth. Most standard files are 8-bit, but 10-bit allows for over a billion colors. This significantly reduces "banding" in dark scenes or skies, making the heavy CGI and atmospheric shadows of this episode look much smoother.
This is High Definition (HD) resolution (1280 x 720 pixels). It offers a sharp image that balances quality with a smaller file size compared to 1080p or 4K. His.Dark.Materials.S03E07.720p.10bit.WEBRip.2CH...
This episode is widely considered one of the strongest in the series, holding high ratings for its emotional weight and for successfully adapting one of the most difficult chapters of the book trilogy. This refers to the color depth
This means the file was captured/encoded from a streaming service (like Max or BBC iPlayer) rather than a Blu-ray disc. WEBRips are generally very high quality and identical to the streaming source. This is High Definition (HD) resolution (1280 x 720 pixels)
If you are looking at this specific file version, here is what those labels mean for your viewing experience: