Learning and instructional design theory is the body of principles proposed by psychologists and educators to explain how people acquire skills, knowledge, and attitudes. Learning theory is used in formal instruction to facilitate and accelerate the learning process. When applied to the practice of instruction, learning principles derived from theories can guide the instructional designer in improving the effectiveness and efficiency of the learning activities of a program. This discussion of learning theory is an attempt to express the human process of learning in terms that can be applied in training and education. The categories of human activity have been delineated by learning theorists. This paper uses those categories to establish a framework for how learning takes place and addresses how learning theory is applied to the selection of instructional strategies as well as the media selected to deliver the instruction. The paper also addresses the fact how, in real life, the various types of learning are integrated. This integration of human activities is discussed in terms of schemas, enterprise theory and metaskills.