What is the difference between “Save to My Lists” and “Add to Cart”?

Both Carts and Lists are used to collect lists of titles that can be requested, printed, emailed, or saved to one’s account for later reference.
http://library.clamsnet.org/screens/cartadd.png A “Cart” is temporary and exists only during a given session. Once you close your browser or navigate away from the CLAMS web site the contents of your cart will disappear.
http://library.clamsnet.org/screens/ico_list_add.gif “Lists” are saved to a patron’s account for as long as desired. These lists can be accessed whenever a patron logs in to My Account. Multiple lists can be maintained in a patron’s account.