What will they consider in an interview either certificates or knowledge?

the use of either of them depends on the interview you are facing. Certain interviewers will be like that they want to know everything you are aware of.

Literally, they do consider both!

Both your certificate and knowledge accordingly are equally important.

Usually, the use of either of them depends on the interview you are facing. Certain interviewers will be like that they want to know everything you are aware of. But some interviewers will not want to keep you calm and thus they will ask what you have done and all…

So, in my opinion, both are equally important and both of them should be taken to interview.