Some biological processes (our examples are DNA expression and a reflex response in the leech) move from step to step in a way that cannot be completely understood solely in terms of causes and correlations. This paper develops a notion of mechanistic information that can be used to explain the continuities of such processes. We compare them to processes (including the Krebs cycle) that do not involve information. We compare our conception of mechanistic information to some familiar notions including Crick’s idea of genetic information, Shannon-Weaver information, and Millikan’s biosemantic information