Molecules interact with each other and they prefer to be in a specific orientation or geometry that is the most energetically favorable. Whatever takes the least amount of work. The equation helps us determine that by separating the energy into different components of physical and electronic characteristics.

In a Force Field we start off small with simple molecular systems and then apply it to larger systems in predicting how atoms will move based on their energy.

So for example, the energy interactions and orientations we use for simple alcohols or carboxylic acids can be applied to lipid membranes and simulating them.

Does that make sense?