In theory, there is no difference between theory and practice. But, in practice, there is.
There are two basic ways to solve problems: start with a comprehensive theory and work out the details, or start with particular facts and develop a theory that ties them together. “Detail people” derive solutions by studying the minutiae of a particular problem. “Big-picture people” fit problems into categories that relate to their overarching theories. Each approach has value, and much problem-solving involves adeptly switching between them.