There are three types of memory: sensory memory, short-term memory, and long-term memory. Sensory memory briefly stores impressions from the senses. Short-term memory acts as a temporary storage for a small amount of information. Long-term memory can store unlimited information indefinitely. Long-term memory includes explicit (declarative) memory of facts and events, and implicit (procedural) memory of skills. Encoding and retrieval are important for moving information between memories. Strategies help with encoding information into long-term memory and retrieving it.