What do the arrows on our packaging mean? They indicate whether the adapter, cable or port can send the signal in both directions. If the signal can go through both directions, so it doesn’t matter which order you use, the adapter, cable, or port is Bidirectional. If theres need of signal conversion, for example convert a DisplayPort™ signal to HDMI™ signal.
Then some adapters, cables or the ports contain a chip or processor that actively decodes the input signal to another output signal. This will be mostly Unidirectional. So, for example, the DisplayPort™ signal can be converted to HDMI™ signal but not otherwise. That requires a another process conversion.
Read more: UNI- AND BI -DIRECTIONAL