The frame of reference is the immovable item and remains at the same place and can be used for guiding some one. For example I am telling you an address by saying that you will cross the mega store and then there will a Ferrari and on the next street is my home. So you kept searching my home and then you called me again. I checked from my window before receiving call and saw that the ferrari was gone. So it took more time which means that the frame of reference choosen was movable item. The frame of reference choosen is always immovable. So here I want to move towards elevator which is immovable so choosed it. Furthermore, ship is movable item and the ocean doesn't specify right direction thatswhy stars were used in the ancient times.
