This document discusses auxiliary memory and associative memory. It defines auxiliary memory as non-volatile memory that is not directly accessible by the CPU. Common forms of auxiliary memory include flash memory, optical discs, magnetic disks, and magnetic tape. Associative memory differs in that it is accessed by the contents of data words rather than addresses, allowing the computer to search for and return all storage locations of a provided data word. While fast, associative memory also consumes more power, costs more, and takes up more space than conventional random access memory.