This is the fifth in a series of computer science videos is about the fundamental principles of Dynamic Random Access Memory, DRAM, and the essential concepts of DRAM operation. This video explains how a memory module can be built using large rectangular arrays of memory cells which maximize the available space. It then explains how a memory module is able to read or write a byte of data, rather than just a single bit, by having multiple arrays of cells arranged in banks. It continues by showing how multiple banks can be incorporated into a single chip, and how multiple chips can be placed onto a single dual inline memory module, that is, a DIMM. The concept of ranks of memory chips is also mentioned. The purpose of a memory channel between the DIMM and the memory controller is introduced, including the principles of quad channel mode and dual channel mode.