How DRAM's are different from SRAM's? Why DRAMs are said to use address multiplexing?

Ans

Dynamic RAM (DRAM) is basically the same as SRAM except that it recollects data for only 2 or 4 ms on an internal capacitor. After 2 or 4 ms, contents of the DRAM should be completely rewritten (refreshed) since the capacitorsthat store logic 1 or logic 0, lose their charges. Whole content of the memory is refreshed with 256 reads in a 2-to-4 ms interval. Refreshing also takes place during a write, a read or during a special refresh cycle.