LTM, an abbreviation for long-term memory, refers to the storage of information in the brain for an extended period. While LTM is a commonly used term, there are numerous synonyms that can be used interchangeably. These include but are not limited to, extended memory, long memory, sustained memory, and durable memory. Long-lasting memory, permanent memory, and persistent memory are also common synonyms. Additionally, some use the phrases enduring memory and indelible memory to describe LTM. Though these words differ in their phrasing, they all refer to the same concept of information being stored in the brain for an extended period.