Logging in a user?

[JL2k]

Hi,
I'm planning on adding a log-in script to my site, I am going to store the users in a database.
The problem I am having, is what's the difference between having a session with cookies, and using cookies seperately?
I can understand how to use a session, but as far as I know, when you close the browser that session ends, so if I was to make the session use cookies, can I set the time-out and things?
Thanks, much appreciated,
Jamie

[JL2k]

Right, I've worked out how to change the length of the session now, so that's solved that problem.
The only thing is, is is possible to set the length of the session using "session_set_cookie_params(3600);" (or another command that does the same thing) after the session has started?

Also, does "session.gc_maxlifetime" set the max amount of time a session is stored on the server? If so, I guess I need to set it to higher than the max client cookie time. Is there any way to set this to infinite though, and they delete themselves according to seperate timelengths?