title: How Windows Indexing Service works?
body: <p>I have a task to implement service with behavior like this one.
  My question is: </p>
  
  <p>How Indexing Service  remember what files was already indexed and what no, what files changed and need to reindex them? </p>
  
  <p>Also, I can stop this service  and then start it after  a few days, it continues to work.
  Does it have its own database with information about files? </p>
  
  <p>Thank you </p>