A banana plug is a type of electrical connector used to join wires to devices, such as speakers or test equipment. It features a cylindrical metal pin that resembles a banana, which allows for easy insertion into a corresponding socket. Banana plugs are commonly used in audio applications and for connecting test leads in electronics. These connectors are popular because they provide a secure and reliable connection while allowing for quick disconnection. They are often used in conjunction with binding posts or amplifiers and can accommodate various wire sizes, making them versatile for different applications in electronics and audio systems.