Memory states

Each page of virtual memory can be free, reserved, or committed.

The transition from a free state to a reserved state is called allocation. Pre-reserving memory (without committing physical pages) enables an application to mark its address space in advance. The transition from a reserved state back to a free state is referred to as freeing memory.

The assignment of physical memory for a previously reserved page of virtual memory is referred to as committing memory, and the inverse transition from the committed state to the reserved state is called returning memory.

Transitions between memory page states