1 <?xml version="1.0" encoding="iso-8859-1"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3 <html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type" /> 6 <title>Cookies, Sessions, Users and Persistent Information</title> 7 <link href="styles.css" rel="stylesheet" type="text/css" /> 8 </head> 9 <body> 10 <h1>Cookies, Sessions, Users and Persistent Information</h1> 11 <p>Due to the nature of the communications mechanisms 12 involved, Web applications do not have automatic or "magic" 13 knowledge about the people or entities accessing them as application 14 users. Moreover, Web applications do not necessarily remember anything 15 about what that user has done before. Due to this behaviour, where 16 every request must tell the application as much as possible for an 17 operation to be carried out, Web applications are referred to as being 18 "stateless".</p> 19 <p>Yet there are a number of ways of maintaining "state" information - 20 that is, to remember the following things:</p> 21 <ul> 22 <li>Some kind of identify for the user, if only to be able to say 23 that such a user has visited before (if not to actually give them a 24 name).</li> 25 <li>Some details about their previous interactions with the 26 application.</li> 27 </ul> 28 <p>Such state information is typically provided using a number of 29 different mechanisms:</p> 30 <ul> 31 <li><a href="cookies.html">Cookies</a></li> 32 <li><a href="sessions.html">Sessions and Persistent Information</a></li> 33 <li><a href="users.html">Users and Authentication</a></li> 34 </ul> 35 </body> 36 </html>