Rather than have process access memory locations directly, virtual memory is to provide a level of abstraction for processes, this abstraction removes many limits imposed by physical properties of the target machine. The first being code needs to be relocatable in memory, it should not matter where the program or its data lies in memory. Virtual memory supports this by giving each application its own logical address space to work in, which will remain valid despite where it is located in physical memory. Virtual memory also gives users of the system that there exists more physical memory than there really is. This is achieve by providing a large virtual address space and swapping in and out data from disk into memory when it is being used.