Walls and Ceilings - Definitions, please...

Can someone please help me with some basic definitions? Or correct/verify my understanding of the below:

Drywall: another word for Sheetrock. This only requires tape and joint compound on the seams and joint compound over screws. Plaster cannot be applied over this.

Blueboard: Entire surface needs to plastered.

Mud: Is this another word for joint compound?

Plaster: Coating to harden walls and provides an attractive surface for eventually painting. Best choice for main living areas, whereas sheetrock and joint compound provides a sligtly less desirable, but still good finished look.

Thank you so much in advance.

You've pretty much got it. Blueboard is used with an application of what is called veneer plaster, without the necessity for lath and multiple coats of plaster as was the original method.

Thanks. I just wanted to make sure I was clear as I read teh various threads on this board. So, just to be sure, as I read the threads, DRYWALL=SHEETROCK and SHEETROCK=DRYWALL?