The memory chip on the memory bar belongs to DRAM chip. RAM is generally divided into two types: SRAM(static random access memory) and DRAM(dynamic random access memory).
The read speed of SRAM is quite fast, and because of its high cost, it is mainly used as a Cache memory in computers.
DRAM although the reading speed is slow, but its low cost, high integration, suitable for the system as a large capacity \"main memory\