Pairing is the process of establishing a connection for the first time between a Bluetooth source device and Dolby Dimension.  Once you've successfully paired, you should not need to pair again.  After the initial pairing, you will connect to the device that has been paired whenever you'd like to use Dolby Dimension. Put another way, pairing is more of a one time set up process and connecting is what you do on a normal basis once the pairing has been done.