Why the ic is called dram or dynamic ram?

Answer 1

In static random access memory (SRAM), the other type of semiconductor memory, the data is not stored as charge on a capacitor but in a pair of transistors called a flip-flop, so SRAM does not require refreshing. The two basic types of memory have advantages and disadvantages. Static memory can be considered permanent while powered on, i.e. once written the memory stays until specifically changed and thus its use tends to be simple in terms of system design. However the internal construction of each static memory cell requires six transistors, compared to the single transistor required for a dynamic RAM cell, so the density of SRAM is much lower and price-per-bit much higher than DRAM. The complexity of the static memory cell is also relatively slow to operate thus static memory tends to have lower bandwidths than equivalent dynamic storage. Writing the capacitor of the dynamic cell is very rapid and write-access times on modern dynamic storage can be in single digit nano-seconds.