Memory theories explain how we encode, store, and retrieve information. One prominent theory is the Multi-Store Model, which suggests that memory consists of three stages: sensory memory, short-term memory, and long-term memory. Each stage has different functions and durations, helping us understand how information is processed. Another important theory is the Levels of Processing framework, which posits that the depth of processing affects how well we remember information. Shallow processing focuses on superficial features, while deep processing involves meaningful analysis, leading to better retention. These theories provide insights into the complexities of human memory.