What is the difference between Sessions and Cookies in PHP?

What is the difference between Sessions and Cookies in PHP?

php session cookies session-state session-cookies

php

How can I check if a user is logged-in in php?

php authentication session session-state

php

PHP session HTTP to HTTPS problem

php http https session-state

php

Sessions not showing but are definitely there as shown from next page

php html session session-state

php

How can I manage separate session states for two different websites on the same hosting using php

php session-variables session-state session-cookies

php

Warning: session_start() failed: No such file or directory

php warnings session-state

php

When should I use setUserState in Joomla?

php joomla session-variables session-state joomla2.5

php