They walk among us. If you spend enough time at an international airport, I guarantee that one will pass right in front of you. They hack, they listen, they watch from the shadows, they examine records, they find and exploit secrets, and they have been around for centuries. They are spies.

In the most simplistic terms, spies gather information which is not publicly known, handing it over to people who will exploit that information against those from whom it was acquired. Spies work in many different professions. They may work for governments, corporations, or even small businesses. Sports teams spy on each other to get an advantage during games. Depending on the seriousness of what was gathered, a spy may be risking imprisonment and even execution. The first rule of the spy is don’t get caught.

Of course, for many of us, the spy has been glamorized in books, movies, and television. You’ve probably heard of James Bond, the suave and cool agent of Her Majesty’s Secret Service created by Ian Fleming. Bond is the ultimate fantasy of what a spy is and does, but there is some truth behind the fanciful tales of 007 and his world. Fleming was a spy during World War 2, and was present when modern spy networks and methods were created.

Spies have a language all their own, with a vocabulary that is important to learn if you are ever to understand them. Not that I am advocating a career as a spy, but if you want to read the books of Tom Clancy or John le Carré, two brilliant but very different authors of spy thrillers, then you need to understand their special vernacular. Or, even if you just want to comprehend some of the stories in the news today, then you should get to know some of these terms and phrases.

• Agent – Someone employed, usually unofficially, as a spy
• Asset – A clandestine source of information
• Bagman – Person who pays agents, assets, and covert operatives.
• Black ops – Covert operations working without any traceable connections to the organization or government employing them
• Blown – The discovery of an agent’s identity or mission
• Bugging – Listening and/or watching covertly using recording devices
• Burned – When an agent or mission has been compromised
• Case Officer – The person in charge of a covert operation
• C.I.A. – The Central Intelligence Agency, serving as the foreign intelligence gathering service of the United States
• Clandestine Operation – A secret intelligence-gathering mission
• Cloak and Dagger – Term applied to any spy. Figuratively, a cloak is worn to conceal the spy’s identity, while the dagger assassinates anyone who gets too close.
• Cold War – The undeclared war between western democracies and Soviet-controlled countries
• COMINT – Information taken from intercepted communications
• Company – Slang term for MI6 or CIA
• Compromised – When damaging information is gathered on an agent, asset, or operation
• Counter Intelligence – The job of working against governments and agents who wish to spy on your country
• Covert – Secretive, and performed without detection
• Dead Drop – A location where secret information can be left without fear of it being found
• Defector – Someone who worked for one side, and now states a wish to work for the opposing side
• Disinformation – Passing along false information
• Double Agent – A spy who pretends to be working for one side, but is really working for another side. A source of disinformation
• Drones – Spy cameras, usually controlled long distance
• Espionage – The practice of spying
• Eyes Only – Valuable information intended for only one person to see
• FBI – The Federal Bureau of Investigation, which is the domestic counterintelligence and federal law enforcement branch of the United States
• Handler – The case officer who handles the agents in an operation
• HUMINT – Information taken from human sources
• Legend – The fictionalized background story of an agent, often with fake documents, giving the agent a false but secure identity
• MI-5 – The domestic security and intelligence agency of Great Britain, officially known as the Security Service
• MI-6 – The foreign security and intelligence agency of Great Britain, officially known as the Secret Intelligence Service
• Mole – A spy working in one organization on behalf of a competing organization.
• NSA – The National Security Agency of the United States, tasked with safeguarding the communications of the government, and intercepting the communications of other governments
• OSS – The Office of Strategic Services, the US spy agency of World War II and the predecessor of the CIA
• PHOTINT – Photographic intelligence, usually gathered by satellites or drones
• Provocateur – Operative sent to incite an organization into acting in an embarrassing or militant manner
• Safe House – A sanctuary for agents, operatives, and/or assets
• Sleeper – An agent living for an extended period in a foreign country and called to service only when absolutely necessary
• Spymaster – The authoritative head of all operations by a unit of spies
• Station – The place where espionage is planned and executed
• TECHINT – Technical information, such as analysis and data, gathered for an operation
• Throwaway – An expendable agent or asset
• Traffic Analysis – Basic facts gained from volumes of information
• U-2 – The world’s most famous spy plane, developed in the Cold War by the US and still used today

Your mission, should you decide to accept it, is to take this information and use it to help you enjoy a spy movie, novel, or television series in English. Should you choose to become a spy yourself, good luck, and hope that you don’t end up a throwaway.

Can you think of any other terms, words, or phrases that I should have included?