Economics and commerce define an end-user as the person who uses a product. The end-user or consumer may differ from the person who purchases the product. For instance, a zookeeper, the customer, might purchase elephant food for an end-user: the elephant.

In contracts, the term 'end-user' becomes a legal construct referring to a non-reseller. This definition characterises the store the zookeeper bought food from as a non-end-user, but the zookeeper as an end-user. This legal construct most often appears in End User License Agreements, also known as EULAs.