A USB hub is a device that expands a single USB port into multiple ports, allowing you to connect several devices at once. This is particularly useful for computers and laptops that have limited USB ports, enabling users to connect peripherals like keyboards, mice, printers, and external drives simultaneously. Most USB hubs come in two types: powered and unpowered. Powered hubs have their own power supply, which allows them to support more power-hungry devices, while unpowered hubs draw power from the computer. They are essential for organizing and managing multiple connections efficiently.