To make a long-distance call, you have to dial an unfamiliar phone number. you are likely to have trouble retaining the number you just looked up. this best illustrates the limited capacity of memory. long-term implicit short-term explicit

I believe the answer is: Short-term memory

Short-term memory is exist in order to give a person a certain level of capacity to actively hold a small amount of information.
This information should be used as soon as possible, because that information would most likely be vanished from our memory within a short period of time.

The best bet is to google