The faculty of the CPU by which data or information is encoded, stored, and retrieved when needed.

A register can store and output values. This is commonly done through 3 channel: Input, Select, and Write. These channel are connected to a each individual memory cell inside the register.

Each cell has it's own input channel, but the select and write channel are linked together; this is done because you generally want to write a entire 8 bit section of cells (one register) to represent some information.

8-Bit Register

Each memory cell can store 1 bit and consist of 3 separat channels (Read, Write and Select), which can be used to either set, reset or output a value.

Simple Memory Cell

RS-Flip-Flop