A boost converter is a type of DC-DC converter that steps up (increases) the voltage from a lower level to a higher level. It works by storing energy in an inductor and then releasing it to the output at a higher voltage. This process is controlled by a switch, typically a transistor, which opens and closes rapidly to regulate the output voltage. Boost converters are commonly used in various applications, such as battery-powered devices, where the voltage from a battery needs to be increased to power other components. They are efficient and compact, making them ideal for use in portable electronics and renewable energy systems like solar panels, where they help optimize energy output.