A more thorough explanation:

Definition: Cover is when a buyer in a breach-of-contract dispute purchases goods on the open market to replace the goods that were promised but never delivered by the seller. According to UCC § 2-712, the buyer can recover from the seller the difference between the cost of the substituted goods and the original contract price.

Let's say a company orders 100 widgets from a supplier for $10 each, but the supplier fails to deliver the widgets. The company then purchases 100 widgets from another supplier for $12 each to fulfill their order. The company can then sue the original supplier for the $200 difference between the original contract price ($10 x 100) and the cost of the substituted goods ($12 x 100).

In another example, a person orders a custom-made dress from a designer for $500, but the designer fails to deliver the dress. The person then purchases a similar dress from a different designer for $600. The person can then sue the original designer for the $100 difference between the original contract price ($500) and the cost of the substituted goods ($600).

These examples illustrate how cover works in a breach-of-contract situation. The buyer is able to purchase goods from another source to fulfill their original order and then recover the difference in cost from the original seller.