Here's a good way to remember the difference between the Transportation Security Administration and U.S. Customs and Border Protection: One is for when you depart, and the other is for when you arrive. It can be confusing to differentiate among the government organizations that are involved in airline travel, but when it comes to the TSA and the CBP, it's not too tricky. The TSA screens passengers as they depart from an airport, and the CBP checks them as they arrive into an airport. There is one similarity, however: Both offer membership programs that get you through more quickly.

Transportation Security Administration

The TSA is a U.S. government entity that screens travelers to ensure safe travel on modes of transportation in the country, especially airplanes. The TSA is based in all U.S. airports, where agents require passengers to pass through a variety of safety checks, including bag screenings and body scanners, on the way to the gate. Passengers are encouraged to arrive two hours before a domestic flight and three hours before an international flight to make it through these screening procedures with enough time to catch their flights. Most screening points use advanced imaging technology, instead of traditional metal detectors, to check passengers for foreign or metallic objects. Some passengers might be subjected to extra bag checks or pat-down screenings if anything looks amiss.

U.S. Customs and Border Protection

The CBP is responsible for securing the borders of the United States at all points of entry, including airports. Travelers arriving into the U.S. must pass through U.S. Customs on the way out of the airport. Both U.S. citizens and foreign visitors are required to show a passport and pass through a customs check, which sometimes includes a bag search. Foreign visitors typically go through a separate line from U.S. citizens and might be required to show additional information like a visa or proof of approval through the Electronic System for Travel Authorization, or ESTA.

TSA Precheck vs. Global Entry

Two programs help travelers pass though TSA and U.S. Customs checks more quickly. TSA Precheck is a five-year membership program that allows travelers to use expedited security lines at the airport. Global Entry is a membership program that allows for preapproved entry into the U.S. Both programs require applications, background checks, a scheduled appointment and a fee. A benefit of Global Entry is that it also includes TSA Precheck.

TSA Precheck allows passengers a quicker journey through security. You're not required to take off your shoes or remove liquids and laptops from your luggage. TSA Precheck members typically go through a designated security line that is shorter than the regular lines. Most airports and airlines accept TSA Precheck, but it is not always offered for those traveling internationally or out of an international airport terminal. Check the TSA website for a full list of places where TSA Precheck is accepted and to see how to apply.

Global Entry helps travelers skip the queues at U.S. Customs by using automated kiosks, where you present your passport and then quickly head toward baggage claim. The kiosks use photo and fingerprint identification. Schedule an application appointment online through the CBP website. A few other programs similar to Global Entry let passengers bypass U.S. Customs more quickly. These include NEXUS, which is a paid prescreening program, and SENTRI, which allows for expedited clearance in designated lanes.