Difference between Cookies and Session in PHP
  • Cookies are stored in the user’s browser memory.A cookie can keep information in the user's browser until deleted.
  • Session : logical object that allows you to preserve data across subsequent http requests.Whenever PHP creates a new session, it generates a session ID.
  • Session values are store in server side not in user’s machine. A session is available as long as the browser is opened. User couldn't be disabled the session. 
  • Cookies are stored in client side and sessions are stored in server side. 
  • Cookies can only store strings.We could store not only strings but also objects in session.
  • we could be save cookie for future reference, but session couldn't. When users close their browser, they also lost the session.