Archived - USB: Descriptions of Ports, Connectors, and Cables
There are two types of USB ports and connectors, Type A and Type B.
Type A ports and connectors are small and rectangular and are typically used to plug a device into a Type A USB port on a computer or a hub. Type A ports and connectors are sometimes referred to as "upstream".
Figure 1 USB Type A port and connector
Type B ports and connectors are small and square and are used to attach a USB cable to a USB device. Type B ports and connectors are sometimes referred to as "downstream".
Figure 2 USB Type B port and connector
Note: Many devices have a "captive," or attached, cable that includes a built-in USB connector.
USB ports on the computer
Your computer has two USB Type A ports; the top port is numbered 1 and the bottom port is numbered 2.
Note: You should plug the Apple USB Mouse into a port on the Apple USB Keyboard, then plug the keyboard into a USB port on your computer. This leaves one open USB port on your computer to which you can connect another device, such as a printer.
USB ports on the Apple USB Keyboard
The keyboard has two USB ports, one on either side. You can plug the Apple USB Mouse into one port, leaving the other port open to connect another USB device, such as an external storage device.
Many USB devices have a captive, or attached, USB cable, such as the Apple USB Keyboard. Other devices come with a standard USB cable that has a Type A connector on one end and a Type B connector on the other end.
Some devices may come with an adapter or adapter cable. Third-party manufacturers may also sell adapters. See an Apple Reseller for more information.
If you're using an adapter or adapter cable to connect a USB device, follow these steps:
1. Plug the adapter or adapter cable into the existing cable from the device.
2. Do one of the following:
- If you're using an adapter cable, plug that cable directly into a USB port on the computer, the Apple USB Keyboard, or another USB device.
- If you're using an adapter, plug a standard USB cable into one end of the adapter, then plug the other end of the USB cable into a USB port on the computer, the Apple USB Keyboard, or another USB device.