In order to move through the Universe, all objects must use energy. Energy means the ability to do work. This is just a fancy way of saying that energy means that objects have the ability to move.

When talking about energy, we often divide it into one of two categories. These categories are potential energy and kinetic energy. Generally, we describe potential energy as energy that an object has because of its position in the Universe. As for kinetic energy, this is described as being energy that an object has by virtue of its motion through the Universe.

To give a straightforward example, when you hold a book above your head, that book has potential energy. If you let go, gravity will work on the book and cause it to accelerate towards Earth at a rate of 9.8 meters per second squared (9.8 m/s2). Once in motion the book no longer has potential energy. Instead, it has kinetic energy.

Another example of potential energy is when objects become contracted or expanded. This means that they are taking on more space or less space than before. As a result of this changing size, objects may have the potential energy to do work in the future if they are allowed to contract or expand through some form of external force.

Take for example a strong metal spring. When we contract the spring we create potential energy. When we let go of the spring that potential energy becomes kinetic energy.

Another way in which objects can obtain potential energy is from chemical reactions or chemical interactions. For example, if we were to combine the elements hydrogen and oxygen we would create a chemical reaction (which is an energy change) and as a result we would make water. The water has the potential of doing work because it can be evaporated into steam which can turn turbines for hydroelectric power stations.

In conclusion, it can be said that potential energy is stored energy. In contrast, kinetic energy is the type of energy that an object has by virtue of its motion through space and time.