What does device priority mean in my Linksys router settings?

In the settings of my linksys router, it say device priority. If i set one of my devices, such as a laptop or PC as a highest priority, does that mean it gets more band width or what? I have to name the device and i put in the mac address for the device. It's in the QoS section.|||Its priority is how important it is and the router is usually really important