Learning is the acquisition of information and/or the internalization of a course of action in order to obtain the desired result or objective. Learning is a consequence of experience. It is measured by an increase in the likelihood of a particular behavioral response to a stimulus. Generally, rewards or punishments, as mentioned earlier, are crucial ingredients of learning, as are contact with and manipulation of the environment. Memory is the relatively permanent storage form of the learned information although, as we shall see, it is not a single, unitary phenomenon. Rather, the brain processes, stores, and retrieves information in different ways to suit different needs.
The term memory encoding defines the neural processes that change an experience into the memory of that experience—in other words, the physiological events that lead to memory formation. New scientific facts about memory are being generated at a tremendous pace, and there is as yet no unifying theory as to how memory is encoded, stored, and retrieved.