I will not claim that I have a very extensive understanding of it, but I probably understand it enough to give you an idea on the concept. Basically entropy is the measure of disorder or chaos in a system. Scattered things have more entropy than closely clustered things, gas has more entropy than liquid, and liquid more than solid. An increase in potential energy causes an decrease in entropy, a decrease in potential energy causes an increase in energy. Because things located farther relative to the center of the Earth has more gravitational potential, they have less entropy than things closer to the center of Earth. The universe favors chaos, therefore things has a tendency toward disorder. So the second law of thermodynamic states that all changes either directly or indirectly increases the entropy of the universe. So basically, entropy of the universe always increases, even if you try to decrease the disorder of a local system, you will still cause a greater increase to the entropy of the surrounding to make the net entropy positive. Because the universe favors disorder, entropy can be used to predict if a change will likely to happen spontaneously. In general if a change causes an increase in entropy (e.g. solid changing to liquid to gas, a deck of card become mixed up when you throw it, things located higher falls down) it will likely happen spontaneously, if a change causes a decrease in entropy it likely won't happen spontaneously ( things going uphill, random metal pieces built themselves into a functioning machine).
Lastly, and the best part, is that the second law of thermodynamics predicts the end of all life. Since the entropy of universe always increases, eventually all potential energy will be used up, and energy will be evenly distributed across the universe, unable to push or pull in any one direction, canceling each other out. Since no energy will be available for use to do work, all life forms will die. This is called a 'heat death' because it mostly results from other energy forms being converted to thermal energy
