These two concepts, while related, are distinct and their differences should be clearly understood. When we predict, we are not interested in knowing why something is going to happen. We simply want to generate a good forecast. The smaller the forecast error, the better the forecast. We want to generate these good forecasts using the simplest forecasts possible.
Explanation is very different.
We change our focus to understand why demand behaves as it does. We want to identify those factors that explain changes in behavior. Consider the following story. The higher the number of umbrellas in use, the greater the probability that the Conservatives would win. This group had a good forecasting system.