First we must learn what an empirical observation is: it is information that is gathered generally from our senses (sight, touch, smell, etc.), hence something making "sense". It must be verified by others and done so repeatedly. The saying "nobody's perfect" is a good explanation why we need to gather the same information from different sources by different people many times. This is in order to ensure that we didn't make a mistake somewhere along the line. This is how we gain reliable information.

Albert Einstein

A theory is a model or explanation of a certain aspect of the universe based on what we know at present and that has been tested to establish its validity. For example, Sir Isaac Newton's Theory of Gravity and Albert Einstein's General Theory of Relativity (gravity) attempt to explain how gravity works. It does not propose that there is this "thing" called gravity and then tries to prove it. Gravity is an empirical observation. If we were to drop a pencil while on the surface of the Earth, it falls at 9.801 metres per second squared. This is repeatable - try it a hundred, even a thousand times and you will get the same result. Get your friends to do likewise. You will observe gravity in action. Theories, on the other hand, try to explain the "how" and "why" of observations. In order to explain gravity, Einstein proposed that space-time is warped, and this seems to be a pretty consistent model that holds up to repeated scrutiny by different researchers.

Sir Isaac Newton