Answer:
Although all RAM basically serves the same purpose, there are a few different types commonly in use today:
1.Static RAM (SRAM)
2.Dynamic RAM (DRAM)
3.Synchronous Dynamic RAM (SDRAM)
4.Single Data Rate Synchronous Dynamic RAM (SDR SDRAM)
5.Double Data Rate Synchronous Dynamic RAM (DDR SDRAM, DDR2, DDR3, DDR4)