Special relativity can be used to study an object in physical events.
Special relativity is Albert Einstein's theory that there is no preferred frame of reference for physics, and all measurements depend upon the frame of reference from which they are made.
If the object is falling down, it is accelerating. "Inertial frames of reference" do not include acceleration, so the falling object can't be considered an inertial frame of reference, according to the Special Theory of Relativity. However, the General Theory or Relativity explores additional complications due to gravity. In any case, if you wish, you can use the object accelerating downward as a reference frame (just don't call it "inertial"); in this case, obviously the room is accelerating upward, compared to the falling object. It all depends what object you choose as your reference frame.
That is Einstein's theory of relativity.
Absolute motion is motion relative to a presumed absolute reference frame. Special Relativity posits that the laws of nature are perfectly symmetrical with respect to any inertial reference frame. This implies that there is no absolute reference frame, and that absolute motion is a useless concept.
According to the Theories of Relativity, time is NOT independent of the reference frame.
It says that the speed of light in a vacuum measured in any inertial frame of reference is equivalent to the speed of light in a vacuum measured in any other inertial frame of reference.
It is exactly 22354786 minutes in duration in the reference frame of the person measuring the passage time (as described by special relativity).
If you are *not* dealing with special relativity and its effects, then the answer becomes far more simple. If you are not moving and are standing on the ground, then you see a train moving past you a fast speed. In this case, the reference "frame" (not necessarily a point) is you and the object being described is the train. If you flipped the roles, then it would be someone on the train watching you as the train moves. However, since it is from the train's perspective, it does not appear that the train is moving, but rather that you are moving away from the train, along with the rest of the world that passes the train by. This is described as the train being the reference frame and you would be the object described by the train. This is, again, just Galilean relativity. Special relativity puts a few twists on it and has some additional effects.
When an object is seen moving in relation to a stationary object is called the frame of reference
Any moving object can be redefined as a frame of reference at rest, from which all other moving frames can be measured. That's a fundamental precept of Relativity. It's motion is defined only in relation to some other object from which the motion is measured, so reselection as the rest frame is necessary, but once established as a rest frame, it is (for the purpose of measurement) no longer considered to be in motion. Since everything is moving in relation to everything else, any frame can be selected as the frame of reference at rest, with all other motion measured relative to it.
Time Dilation and Length contraction (essentially the same idea, whenconsidering the sameness of time and space as dimensions - which is the crux of special relativity), and specifically the Precession of Mercury (which is predicted by General Relativity) [which forgoes the necessity of a background reference frame (an axis/coordinate system)] are examples of Relativity.
The stationary object is known as a frame of reference. The earth is a common frame of reference for humans.