An external mouse is a peripheral device used to control a computer's cursor and interact with its interface. Unlike a built-in touchpad, an external mouse connects to a computer via a USB port or wirelessly through Bluetooth. It typically features buttons for clicking and a scroll wheel for easy navigation. External mice come in various shapes and sizes, catering to different user preferences. Some are designed for gaming, offering additional buttons and customizable settings, while others focus on ergonomic designs to reduce strain during prolonged use. Popular brands include Logitech, Razer, and Microsoft.