A USP, or Unique Selling Point, is a feature of a product or service that distinguishes it from other similar, competing products & services in a positive way.
Having a Unique Selling Point is incredibly important when bringing new products/services to the market; helping find an appropriate and successful market position. One example of a USP would be a significantly lower price-point than similar products on the market, which helps appeal to customers who are on a budget. On the other hand, in the technology sector, a new product is more likely to be designed with a new innovation that other competitors do not have in their products to create consumer desire for newer, more advanced products.
Having a strong USP allows a brand to have an impactful focal point in its marketing; starting with a desirable product/service and building around that.