As the Senate considers legislation restricting gun purchases by people on terror watch lists, it's important to understand what list they're talking about. Here are definitions of key ones: Consolidated terrorist watchlist Covers about 1.1 million people Includes individuals suspected by the federal government of being involved in terrorist activities or associated with people who are Created in 2003 No-Fly and Selectee lists Covers about 109,000 people, including 2,500 Americans. The no-fly list includes individuals prohibited from flying in or out of the United States because they are considered by the federal government of being a direct threat to U.S. civil aircraft The selectee list includes individuals who will receive additional screening before flying because of concerns that they are a threat to U.S. civil aircraft Created in 1990 Sources: Government Accountability Office, FBI, Congressional Research Service Contact Bennett at johnbennett@cqrollcall.com and follow him on Twitter @BennettJohnT . Get breaking news alerts and more from Roll Call on your iPhone or your Android.