Question

What is the capacity of the long-term memory system?

Answer 1

Theoretically, the capacity of long-term memory could be unlimited, the main constraint on recall being accessibility rather than availability. 

Answer 2

Theoretically, the capacity of long-term memory could be unlimited, the main constraint on recall being accessibility rather than availability. Duration might be a few minutes or a lifetime. Suggested encoding modes are semantic (meaning) and visual (pictorial) in the main but can be acoustic also.