In computer science, a memory map is a structure of data that indicates how memory is laid out. The term memory map has different meanings in different contexts.It is the fastest and most flexible cache organization that uses an associative memory. The associative memory stores both the address and content of the memory word. In the boot process of some computers, a memory map may be passed on from the firmware to instruct an operating system kernel about memory layout. It contains the information regarding the size of total memory, any reserved regions and may also provide other details specific to the architecture. In virtual memory implementations and memory management units, a memory map refers to page tables or hardware registers, which store the mapping between a certain process's virtual memory layout and how that space relates to physical memory addresses. In native debugger programs, a memory map refers to the mapping between loaded executable or library files and memory regions. These memory maps are used to resolve memory addresses to actual symbols.