frame of reference
noun[C]
us/ˈfreɪm əv ˈref·ər·əns,ˈref·rəns/pluralframes of referencea set ofideasorfactsthat apersonacceptsand thatinfluencesthe person’sbehavior,opinions, ordecisions:
Thereportprovidedacommonframe of reference fordiscussingpublicpolicy.
physics
A frame of reference is also asystemoflinesandclocksthat you can use tomeasurethepositionandmotionof a set ofobjectsandeventsinrelationto each other.