A USB charger is a device that provides electrical power to charge various electronic gadgets, such as smartphones, tablets, and laptops. It typically connects to a power source, like a wall outlet or a computer, using a USB cable. The charger converts the electrical current to a suitable voltage for the device being charged. USB chargers come in different types, including USB-A, USB-B, and USB-C, each with unique connectors. They can vary in power output, measured in watts, which affects how quickly a device charges. Many modern chargers support fast charging technologies, allowing for quicker power replenishment.