Used smartphones are pre-owned mobile devices that have been previously owned and used by someone else. They can vary in condition, from like-new to heavily worn, and are often sold at a lower price than new models. Many people choose to buy used smartphones to save money or to access older models that may no longer be available in stores. Purchasing a used smartphone can be a smart choice, but it's important to check the device's functionality and condition before buying. Buyers should look for reputable sellers, such as certified retailers or online marketplaces, and consider factors like battery life and warranty options to ensure a satisfactory purchase.