What is the difference between internalism and externalism?

In the field of epistemology internalism and externalism are the main methods by which we understand the world and acquire knowledge. Externalism, also sometimes termed inductive empiricism, is the observation of specific facts to then, by an effort of abstraction, arrive at conclusions of general validity. Internalism, often likened to rational deduction, is the use of established precepts to draw conclusions about specific cases.