PHP & Sessions / Cookies
Sessions and cookies enable user login information, preferences
and more to be stored without any user intervention. PHP
sessions are great for temporary login storage, to keep users
logged in at a site until the browser is closed. This makes
sessions very safe and secure. However, cookies can save website
preferences for a year, far longer than sessions. And cookies
are stored on the user's computer, whereas sessions reside on
the server.
Giving users the option to choose which one they want to use can
be helpful if their browser doesn't support one or the other.
And with the simplicity of PHP, using either of these
simultaneously on your website should be seamless to endusers.