"SRAM is also used in personal computers, workstations, routers and peripheral equipment: internal CPU caches and external burst mode SRAM caches, hard disk buffers, router buffers, etc." Says Wikipedia on SRAM.
It's basically a small cache for buffering most likely being used by the CPU.
Nope, they don't (and won't!) match up at all - the two are very different things.
I could write an essay here on the differences, but it basically boils down to static RAM (that's the SRAM) being very fast and very expensive (hence it's low size) and dynamic RAM (that's the system or normal RAM) being slower but a lot cheaper. If you want to know more in depth, Google will bring up a ton of results!