The disadvantage of dynamic RAM over static RAM is?
The disadvantage of dynamic RAM over static RAM is need to refresh the capacitor charge every once in two milliseconds.
The advantage of a DRAM is the simplicity of the cell - it only requires a single transistor compared to around six in a typical static RAM, SRAM memory cell. In view of its simplicity, the costs of DRAM are much lower than those for SRAM, and they are able to provide much higher levels of memory density.
SRAM (static RAM) is random access memory (RAM) that retains data bits in its memory as long as power is being supplied. Unlike dynamic RAM (DRAM), which stores bits in cells consisting of a capacitor and a transistor, SRAM does not have to be periodically refreshed.