What does the consesus layer currently do ?

I have a good understanding on how the execution layer currently works but I fail to understand what happens on the CL right now. I know it's proof of stake but are there any transactions happening on that layer ? If not, what are the stakers validating ?

Also, will we still have both an EL and a CL after the merge ? I'd love to understand it in more detail (give me some maths <3) but I think I need a broad understanding beforehand.

Thanks