Answer:
In physics, the concept of a frame of reference is used to specify the perspective from which an object or event is observed.
A frame of reference is where the measurements or observations will be made. Because of this, observing an event may be different when changing from one frame of reference to another, because the measurements will be different.
Defining frames of reference is necessary because the movement is relative, it may be that from our perspective or from a frame of reference on earth we are at rest, but seen from a frame of reference in space, we are in motion due that the earth is always moving.
Another example of frames of reference is a moving plane. Seen from the ground an object in the plane moves at the speed at which the plane travels, but if the frame of reference is fixed on the plane, the object is at rest.
