title: when to use index.php instead of index.html
body: <p>I am relatively new to php. There is a very basic thing that has been troubling me. I understand that php is used to make web sites dynamic. I also understand that php is one of the many server side scripting languages that can be used to make dynamic web sites. </p>
  
  <p>However, what I do not understand is that when do i need to use an index.php page. Say for example if i have just a simple login page on my index page, it could very well just be a simple html page as well. Right? Then why would i want to make it index.php instead of index.html? </p>
  
  <p>An example of a sample situation would be great.</p>