Php Login System
 

Allright well a login system is what I have to do next... So To start I have a question. How does the code know that your logged in?

a cookie or a session. Cookie is the most preferred.

Ah i see...

Er... You mean a cookie or a GET/POST variable?

A session is a device which ties a series of HTTP requests together, using a cookie or GET/POST variable.

The script knows you're logging in via a get/post variable, but I was talking about how once you're logged in the system knows that by a cookie or session variable

Session ID are usually carried in cookies, with GET/POST variables as fallbacks. I suspect what you mean is that one shouldn't put login information directly into a cookie, and you'd be right. But don't think that sessions don't use cookies.

I know they do, but it's more like a cookie variant and they aren't stored in the same place ($_COOKIE[] and $_SESSION[] respectively), I was simply differentiating for the sake of showing it.

Bleh. You confused me :p

my bad ;)

the webserver has a setting for php which decides to store sessions as cookies only, or as cookies first and get/post as fallback, or just get/post. GET is pretty insecure to have your information in.
Normal login steps are.
Have a form to enter login information
Send form via POST to a php script
Have the php script verify login information
Have the script start a session (search for session at php.net for functions) with your username or some other identifier
Whenever you need to use that information, access it through $_SESSION['variable']