Definition: Have you ever wondered why it is so hard to remember some things (like important dates for your history exams), while you remember other things with no effort at all (like the lyrics to a catchy pop song)? Both of these examples represent different types of long-term memory. Things that we have to consciously work at to remember, like a phone number or information for a test, are stored in explicit memory. Those things that we don't intentionally try to remember, such as a familiar song or various daily habits, are stored in implicit memory.
Learn more about how this process works in this overview of implicit and explicit memory.