A DC-DC converter is an electronic device that changes direct current (DC) voltage levels. It can either step up (boost) or step down (buck) the voltage, making it useful for various applications, such as powering electronic devices from batteries or adapting voltage levels for different components in a circuit. These converters are essential in many modern technologies, including solar power systems, electric vehicles, and portable electronics. By efficiently managing voltage levels, DC-DC converters help improve energy efficiency and extend the battery life of devices, ensuring they operate effectively under varying conditions.