A port is a connector at your computer that allows you to plug in an external device like a printer. The port allows instructions to flow between the computer and the device.
There are different ports to connect the monitor, the mouse, and the keyboard. There are also ports that allow you to connect games or that connect you to other computers.
Just about any computer that you buy today comes with one or more Universal Serial Bus or USB connectors. USB is a type of port that allows you to connect many devices to the same port.
For example, you can use a USB Port to connect a printer, modem, joystick, and scanner to your computer. Compared to other ways of connecting devices to your computer USB devices are incredibly simple!