In retail marketing, an endcap is a display for a product placed at the end of an aisle. It is perceived to give a brand a competitive advantage. It is often available for lease to a manufacturer in a retail environment. Products placed on an endcap for sale will sell at a much faster pace than products not on the endcap. The display of products on the endcap is sometimes also called a feature.
Promotional shelves and retail fixtures
In addition to products displayed on the end of an aisle, promoted space on a retail shelf can be referred to as a fixtures. Companies will oftentimes purchase a smaller amount of shelf space before making the move to an endcap at the end of an aisle.
References
Endcap Wikipedia(Text) CC BY-SA