Cart Retention Settings

This setting controls how long (in days) a shopping cart will remember what’s in it before it clears automatically.

When someone adds items to their online shopping cart but doesn’t finish the purchase, the system saves that cart for a while.

• This setting lets you choose how many days the system should remember that cart.
• After that number of days, if the person hasn’t checked out, the cart will be cleared automatically.

So basically it decides how long a shopper’s cart stays saved before it expires.