USB
Universal Serial Bus (USB) is now a standard serial communication port on modern computers.
USB uses a tiered star topology with each branch having a maximum length of 5m but can be limited to 3m for higher speeds.
The USB version numbers for the cables and thus, their rated speeds, are separate from the version numbers for USB connectors.
One example of USB cable and connector specification being separate is the use of a USB C connector for a USB2 cable. In this case, the device is only capable of USB2 but takes advantage of the size and that it can be inserted either way (ie. a reversible connector).
USB 1.1 & USB 2 connectors typically have white or black plastic in the connector. The connectors and cables have fewer wires than the USB 3 connector which typically uses blue plastic. (see USB background)
The USB connector originally used Type-A for upstream and Type-B connectors for downstream directions. This was to help prevent illegal loopback connections such as joining two USB ports on the same hub or computer.
USB Type-A connectors plug into an upstream device towards the computer. Type-B connectors plug into a downstream device such as a Camera or Focuser.
The version numbers for USB ports, cables and connectors are important. For example, a USB 3 camera must have USB 3 cables and USB 3 Hubs in the cabling between the camera and the computer. The computer USB port must also be USB 3. If all of these conditions are not met, at best the connection will only work at USB 2 speeds and at worse, incompatibilities can cause issues.
A USB 2 device can use a USB 2 cable and plug into either a USB 2 or USB 3 Hub.
In summary, the computer port cables & hubs must be at least the same USB version, or higher, as the USB version used in the Astro device needing a connection to the computer. (see USB Hubs)