I really think we should merge 2 tags out of these 3:
because they're too similar. There are even 11 questions tagged with all of them.
I also think we can merge resolution and screen-resolution (look at the top questions of resolution - they obviously relate to screen resolution.)
I know some might refer to resolution not in a screen, but that's why it would be smarter to merge screen-resolution into resolution. One can also tag with screen resolution.