title: How does drupal connect to the database
body: <p>I am really new to drupal and new to php.
  I have some questions.
  Suppose I have a drupal and a server running on my local machine, how does drupal interact with database? (database is mysql)
  it doesn't matter which version of drupal it is, I just want to know how drupal interacts with database.</p>
  
  <p>Thank you!</p>