long term memory

This term describes the brain's capacity for permanent or semi-permanent storage, contrasting sharply with short term memory, which is transient and limited in capacity. It is primarily used in psychological, neurological, and medical contexts to describe cognitive function and the effects of brain injury or aging.

As a conceptual noun referring to a biological system, it is treated as an uncountable mass noun. It does not typically take a plural form because it refers to the general faculty of memory rather than individual instances of remembered items.