Used books are pre-owned books that have been read and sold again. They can come from various sources, such as libraries, individuals, or bookstores. These books often show signs of wear, like creased pages or faded covers, but they can still provide valuable content at a lower price than new books. Buying used books is an eco-friendly choice, as it promotes recycling and reduces waste. Many readers enjoy the charm of used books, as they may carry a history of previous readers. Popular places to find used books include thrift stores, online marketplaces, and local bookstores.