The adjective proactive can describe a person who gets things done. If you are proactive, you make things happen, instead of waiting for them to happen to you.
Active means "doing something." The prefix pro- means "before." So if you are proactive, you are ready before something happens. The opposite is being reactive, or waiting for things to unfold before responding. Think about winter cold season. A proactive person washes his hands and takes vitamins; a reactive person gets sick and takes cold medicine.