PC Memory Unit is a term used to describe the storage capacity of a computer. It is composed of two components: Meg (3 letters) and Byte (4 letters). Meg stands for Megabyte, which is a unit of measurement for digital information and is equal to one million bytes. Byte is a unit of measurement for digital information and is equal to eight bits. Together, these two components make up the PC Memory Unit, which is used to measure the amount of data that can be stored on a computer.