The document discusses the key stages and types of memory: 1) Sensory memory briefly stores sensory information, working memory actively processes information, and long-term memory stores information more permanently. 2) There are three main types of memory - implicit procedural memory which affects behavior unconsciously, and explicit episodic and semantic memory which can be consciously recalled. 3) Memories are encoded, stored, and retrieved, but can also be forgotten due to interference, failure of encoding or retrieval, or decay over time if not rehearsed.