title: Uses of Business Logic Layer
body: <p>I know this may be a duplicate question. But i never found a correct explanation that a beginner like me can understand.</p>
  
  <p>My question is "What all things we can do inside Business Logic Layer".
  I have done 3 tier architecture projects. But I used BLL only to pass values between UI and Data Layer. </p>
  
  <p>But whenever i attend an interview they asks me what all things you do inside BLL.<br>
  Please help me to understand the correct use of BLL.<br>
  Please provide little bit of sample code if you can.</p>