Different between Flash over & Back Draft ?

Flashovers Is a the sudden involvement of a room or an area in flames from floor to ceiling caused by thermal radiation feedback. Backdraft is a smoke explosion that can occur when additional air is introduced into a smoldering fire and heated gases mix with a flammable range and ignite with explosive force   Backdrafts and flashovers are equally dynamic and deadly. Recognizing the signs and being able to remain calm will give you the best chance for survival. It goes without saying that you should be in full protective equipment.

Back Draft , when fire consumed all the oxygen in enclosed area leaving heat ,fuel ,when sudden entrance of the air in this enclosed area the fir again start in the form of explosion.it is called back draft .Air ( Oxygen ) play an important role in back draft . 

Flash Over, flash over happen when enclosed area the temperature reach at the fire burning level (500c') or 970 f ' ) all the thing start to burn simultaneously this is called flash over , Heat play an important role in flash over.