Explain what it means to view something from a frame

A frame of reference is a point or set of fixed points relative to an object describing a motion, and affects on the movement you perceive for the object.

For example, if you throw a stone from the window of a car, you'll see a different trajectory depending on whether you take the road or the car as the frame of reference. On the first situation you'd notice a trajectory, while from the car you'd see the stone almost falling to the ground only.