What are the components of an LLM agent's memory, what does each one store, and how is information written to and read from it?

Working memory is the context window: task, recent turns, tool results. Session memory keeps the conversation plus a rolling summary. Long-term memory is episodic (past events), semantic (facts and preferences) and procedural (instructions and skills).

Writes: after a turn, an extraction step decides what's worth keeping, timestamps it and updates conflicting facts. Reads: retrieve by relevance, recency and importance, then fit the results into the prompt's budget.