What are the different kinds of RAMs and how do they differ basically?

Answer 1

RAM can differ in the connector type such as in DIMMS, SIMMS, RDAM and such. They can also be single inline memory modules (SIMMS) or Double inline memory modules (DIMMS) meaning they have memory componets on both sides of the board.

They can also differ by there read and write speeds to memory. This is CAS or memory latency speed. Memory is often rated as CAS1.5, 2, 2.5 or 3 which refers to the different number of clock cycles it takes to do a read from a memory location on the modules.