Complex sentence: It supports vastly larger amounts (theoretically, 2 64 bytes or 16 exabytes) of virtual memory and physical memory than is possible on its 32-bit predecessors, allowing programs to store larger amounts of data in memory.
Split into simpler sentences: It supports vastly larger amounts (theoretically, 2 64 bytes or 16 exabytes) of virtual memory and physical memory than is possible on its 32-bit predecessors. Thus the actual address space is 256TB.Allowing programs to store larger amounts of data in memory.