The difference between Static Random Access Memory and Dynamic Random Access Memory is in the way they hold data: DRAM requires data to be refreshed at regular intervals while SRAM does not require data to be refreshed periodically as long as the power supply remains intact. For this reason, the two types of RAM are also structurally different.
SRAM and DRAM are the two types of random access memory and each has its own pros and cons. DRAM is generally slower than SRAM due to the additional circuitry needed for the data refresh cycles.
A DRAM chip comprises several memory cells. Each cell holds only one bit of information and is made of a capacitor and a transistor. Of course, these are extremely minute parts and thousands of them can fit into a single memory chip. One major complication introduced by the additional circuitry in DRAM is that it requires more power to refresh the data. This difference has significant implications in devices that use batteries.
The technology used in SRAM requires the memory cell to have more transistors in order to hold a specific amount of data. For this reason, a memory cell in SRAM eats up more space on a chip compared to a dynamic memory cell. Thus, SRAM gives users less memory per chip and brings about a big cost difference between the two.
In short, SRAM is fast and pricier while DRAM is slower and cheaper.