session_set_cookie_params what does it mean ?

[eluser]hoapq[/eluser]
As i understand : cookie : a pie information is stored in client browser, and session is store in server. I read php manual : "session_set_cookie_params Set the session cookie parameters". But i don't understand how to set session cookie, session is session, cookie is cookie. where this function effect : client or server.

Thanks.

[eluser]WanWizard[/eluser]
You only need that if you use PHP's own session management.

The CI session library will take care of this for you, you only need to set the proper configuration in the config file.