title: What is the maximum addressable space of virtual memory?
body: <p>Saw this questions asked many times. But couldn't find a reasonable answer. What is actually the limit of virtual memory?</p>
  
  <p>Is it the maximum addressable size of CPU? For example if CPU is 32 bit the maximum is 4G?</p>
  
  <p>Also some texts relates it to hard disk area. But I couldn't find it is a good explanation. Some says its the CPU generated address. </p>
  
  <p>All the address we see are virtual address? For example the memory locations we see when debugging a program using GDB.</p>
  
  <p>The historical reason behind the CPU generating virtual address? Some texts interchangeably use virtual address and logical address. How does it differ?</p>