A class of random access memory that requires periodic servicing in order for the contents to remain valid is

A class of random access memory that requires periodic servicing in order for the contents to remain valid is Dynamic RAM. Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxide-semiconductor (MOS) technology.