According to Wikipedia, a proximate cause is immediately responsible for causing something observed, and ultimate cause is considered the underlying or real cause. Separating these two meanings leads to better understanding of events.
Since ultimate causation cannot be measured but proximate causation can, it is said to be unquantifiable. Ultimate factors are sometimes called root causes because they are realized only when examining deeper layers of proximate factors. Proximate factors are grouped together to form a set of proximate causes that represent a hypothesis. Yet, proximate and ultimate causes deal with questions of how and why and both have applications in other fields. Wikipedia notes that in biology, ultimate causation deals with evolutionary forces that affect traits, and proximate causation deals with biological functions as a product of environmental and physiological factors. According to Ohio State University, in behavioral ecology, scientists use ultimate causation to question the evolution of a behavior and proximate causation to question the mechanics of a behavior. Similarly, in sociology, proximate causation examines reasoning from an individualistic perspective, while ultimate or distal causation relates reasoning to the broader social structure in which the individual operates. In addition, Greek philosopher Aristotle came up with four causes for any natural event: material, efficient, formal and final.