The first-sale doctrine is a legal concept playing an important role in U.S. copyright and trademark law by limiting certain rights of a copyright or trademark owner. The doctrine enables the distribution chain of copyrighted products, library lending, giving, video rentals and secondary markets for copyrighted works (for example, enabling individuals to sell their legally purchased books or CDs to others). In trademark law, this same doctrine enables reselling of trademarked products after the trademark holder put the products on the market. The doctrine is also referred to as the "right of first sale," "first sale rule," or "exhaustion rule."