The Four Types of Memory

Both the "Practical Guide" and the "Building Long-Term Memory" article borrow a framework from cognitive science: human memory is not one thing but several specialized systems working together, and the same split is useful for agents. The "Practical Guide" describes four temporal scopes, organized by how long the memory lasts. This chapter walks through all four, using the glossary entry as the quick reference and going deeper here.

A helpful way to keep them straight before we start: working memory is what you are thinking about right now, episodic memory is your diary, semantic memory is your encyclopedia of facts, and procedural memory is your set of habits and skills.