title: What is resident and dirty memory of iOS?
body: <p>Can some one please tell me, what kind of memory is dirty/resident, and where do they come from?
  Does resident memory means the same with "wired memory" of Mac OS?</p>
  
  <p>this is what I saw about Mac OS memory:</p>
  
  <blockquote>
    <p>Wired : This refers to kernel code and such. Memory that should not
    ever be moved out of the RAM. Also know as resident memory.</p>
    
    <p>Shared : Memory that is shared between two or more processes. Both
    processes would show this amount of memory so it can be a bit
    misleading as to how much memory is actually in use.</p>
    
    <p>Real : This is the "real" memory usage for an application as reported
    by task_info() - a rough count of the number of physical pages that
    the current process has. (RSIZE)</p>
    
    <p>Private : This is memory that a process is using solely on it's own
    that is used in Resident memory. (RPRVT)</p>
    
    <p>Virtual : The total amount of address space in the process that's
    mapped to anything - whether that's an arbitrarily large space for
    variables or anything - it does not equate to actual VM use. (VSIZE)</p>
    
    <p>Active : Memory currently labelled as active and is used RAM.</p>
    
    <p>Inactive : "Inactive memory is no longer being used and has been
    cached to disk. It will remain in RAM until another application needs
    the space. Leaving this information in RAM is to your advantage if you
    (or a client of your computer) come back to it later." - Mac OS X Help</p>
    
    <p>Free : The amount of RAM actually available without any data.</p>
  </blockquote>