The two faces of customs: To most people, customs is just another stop in the airport, but to smugglers, customs agencies are a highly mobilized border guard.

Photo courtesy U.S. Customs Service, photographers Gerald Nino and James R. Tourtellotte

One of the little rituals all international travelers go through is customs. To most people, this is just another stop in an airport or a minor inconvenience at a country's borders. But when you go through customs, you are actually taking part in a key component of the global economy.

In this article, we'll find out what customs is for and how it operates. We'll also look at some of the major obstacles customs agents face and the equipment they use to meet those challenges. When you see everything that customs agencies do, it's clear that they are one of the most essential pieces of a nation's government.