Storage is the second stage of memory, following encoding and preceding retrieval. It refers to the retention of encoded information over time. Storage can be brief, as in sensory memory lasting less than a second, or enduring, as in long-term memory that can last a lifetime.

Information is stored through changes in synaptic connections and, for long-term memories, through structural changes in neurons and protein synthesis. The capacity and duration of storage vary by memory system: sensory memory holds a large amount of information very briefly, short-term memory holds about seven items for 20–30 seconds, and long-term memory is essentially unlimited in capacity and duration.

Memory systems

• Sensory memory: very brief, large capacity
• Short-term memory: ~7 items, 20–30 seconds
• Long-term memory: unlimited, potentially permanent
• Consolidation stabilises long-term storage