Psychologists distinguish between three necessary stages in the learning and memory process: encoding, storage, and retrieval. Encoding is defined as the initial learning of information; storage refers to maintaining information over time; retrieval is the ability to access information when you need it, or in other words the ability of activating knowledge.
There are some popular practises for improving retrieval like spaced repetition that help put knowledge in one’s long term memory in which it can be accessed more reliably (although it may be slower). learning as long-term development Bloom’s taxonomy of learning outcomes