I'll explain one at a time. Descriptive analytics...

attempts to determine what is the best course of action to take in the future. It analyzes what, when, and why a given scenario might happen.

looks to uncover trends in data sets. It answers questions such as$,$ "what happened?" or$,$ "what is going on that causes a specific outcome?"

focuses on the future by using probability analysis techniques with data mining and statistical modeling.