Now that you have completed the unit, what do you know about motion compared to when you started? How do things move?

Before I had learned about motion I thought that when something was moving, another object must be touching it or pushing it. Later on I had realized that in order for an an object to be in motion the reference point or a stationary object has to be changing distance from it. Objects that are moving, the reference point of that object must be changing. A reference point should be stationary in order to see if an object is in motion. However, suppose you're on a train, you are moving reference to the ground, not the train. So, therefore, you are not in motion.