How OSPF Routers inside an area elect a DR and BDR ? and why ?

In broadcast type OSPF network the DR and BDR are selected by the priority value. in this type of networks default priority value is1 and the range is0-255.we  can set the priority value. hence the highest priority value is choosen as DR and second highest as BDR. if it is in default state then the highest router ID is taken as DR.

when DR is down then BDR acts as DR.

This is what i know.