Typical examples of combinational circuits are AND, OR, NOR, NAND, XOR and NOT gates, data selectors (multiplexers). demultiplexers, static RAM, ROM, PROM, EPROM and EEPROM. These are basically circuits that provide a preprogrammed output for any given input.
The most common sequential circuits USUALLY involve a clock, as exemplified by flip flops, counters and shift registers.
My research has shown that the main difference between RS and SR is that the RS version is a flip flop while the SR version is a flop flip.
Dean