Encapsulation

In a TV commercial from a few years back, two people discuss all the money they'll save if they dial a particular 7-digit prefix before dialing a long-distance phone call.
One of them asks, incredulously, “How does it work?”
The other replies: “How does popcorn pop? Who cares?”
An object carries out its operations hidden from the rest of the world.

In a TV commercial from a few years back, two people discuss all the money they'll save if they dial a particular 7-digit prefix before dialing a long-distance phone call.