Channel Keywords vs. Tags

[PinProject]

What's the difference between channel keywords and adding tags to a specific video? I've attached what I mean by channel keywords if some of you are not sure what I'm referring to.
When I look at the search terms people use, a lot of the times its word that are available in my channel keyword and not the tags I have for that specific video.

 

[Jawad Soomro]

Tags are used for videos while Keywords for type of channel!
People will search for specific channels using the filter, if they type DIY, your channel will be in list, but if people are searching for videos, then Tags will be used to refine the search

 

[Paulie Popcorn]

Ahh that makes sense.