When abraham describes to his friend what he did in his last summer vacation, he relies on his memory?

The answer is long-term memory Memory is that part of the brain where information is encoded, stored, and retrieved. The human memory is categorized into three, namely: sensory memory (duration is normally less than a second), short-term memory (duration is normally not more than 1 minute) and Long-term memory (the storage duration can be life-time). It is in the long-term Memory where information concerning experience, skills, tasks, facts, events, concepts and one conscious is stored. So in the case where Abraham describes to his friend what he did in his last summer vacation, he relies on his long-term memory.