title: CPU Switches from User mode to Kernel Mode : What exactly does it do? How does it makes this transition?
body: <p><strong>CPU</strong> Switches from User mode to Kernel Mode : What exactly does it do? How does it makes this transition?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>Even if it is architecture dependent please provide me with an answer. The architecture is up to you. Tell me for the architecture you know about.</p>
  
  <p>I want to get an idea about what all things will be involved in it. </p>