title: How does the Firebase Value event listener works?
body: <p>If I'm using firebase value event listener for real time database, will it continuously query in a specific interval time from the app? If yes what is that interval time?  </p>
  
  <p>Will it increase my bandwidth consumption (considering my data is not changed in my database)?</p>
  
  <p>Of course I can use single event listener, but just trying to understand firebase syncing process</p>