DRAM 101

Everyone knows intuitively that RAM is computer "memory" that allows "random access" (access any location in memory in any order in constant time). RAM normally refers to volatile memory where information is lost when power is turned off.

But what is the difference between dynamic and static RAM? In static RAM, an electronic component known as a flip-flop (aka bistable (Two State) multivibrator) stores 1 bit of memory, in DRAM this bit is stored instead as charge on a capacitor or transistor gate.

The physical implementation of flip-flops is covered here.