Groups of airlines that cooperate on a large scale for their mutual benefit. In terms of miles redemption, this means that the miles of one member of the alliance can be used to fly any other member of that alliance. There are currently three major alliances: Star Alliance, Oneworld and Skyteam.

Applying for multiple credit cards on the same day.

The once-a-year fee that rewards cards almost always have. Some cards waive this fee for the first year, others do not. The amount varies greatly depending on the card, but can be as low as $60 or as high as $450.

The flight you get when redeeming your miles or points.

A noun that is used to describe getting a batch of credit cards at one time. Also known as an “App-O-Rama.” Not to be confused with the verb “churning.” See below.

Airlines that are partners, but not members of the same airline alliance. For example, American Airlines and Ethiad have a codeshare agreement and their miles are redeemable for flights on each other, even though they’re not in the same alliance.

Fees (often in the hundreds of dollars) attached to award bookings. In extreme cases, these raise the cost of the ticket to the point where it defeats the purpose of using miles at all. Often the bane of otherwise great redemptions. Flights on British Airways are the most egregious example of fuel surcharges.

A extremely effective tactic for dealing with incompetent or unhelpful phone agents. You politely thank them, hang up, then call right back and hopefully you get a better representative.

A connecting flight. Flying to one city, never leaving the airport, then flying to another city.

Informal term used to refer to the plane of a specific airline. For example, if you are on a United flight, you are said to be on “United metal.”