"The problem with the world is that everyone is a few drinks behind."

TSA PreCheck is a government-run membership program that allows travelers to use an expedited airport security line. In these dedicated lines, travelers undergo a less-intrusive airport security screening than other passengers.

At airport security, members go through metal detectors instead of full-body scanning machines and can keep their shoes and light jackets on. Additionally, they can leave their laptops and 3-1-1 liquids in their suitcase or carry-on bag.

Children 12 and under can use the PreCheck lane when traveling with a parent or guardian who has PreCheck without registering, but anyone 13 or older needs to register separately.

TSA PreCheck is available at more than 200 airports throughout the U.S. with 83 participating airlines. This program is intended for domestic use only, so there are no international airport locations.

Global Entry membership is run by the federal government and is geared toward the international traveler and allows expedited immigration screening upon entry to the U.S. This benefit speeds up the entry process when international travelers are returning to the U.S. after visiting a foreign country. Global Entry membership also includes TSA PreCheck, so you can double up on benefits with just one program.Unlike TSA PreCheck, Global Entry membership is necessary for people of any age and families can not use Global Entry unless every single family member is a member.

Members can use Global Entry ports of entry in the U.S. and select pre-clearance locations around the world. Some international airports allow members to clear immigration and customs prior to departure instead of when you arrive in the U.S. These airports include Dublin and Shannon in Ireland; Aruba; Freeport and Nassau in The Bahamas; Bermuda; Abu Dhabi, United Arab Emirates; and Calgary, Toronto, Edmonton, Halifax, Montreal, Ottawa, Vancouver, Victoria and Winnipeg in Canada.

Unlike TSA PreCheck and Global Entry, NEXUS is designed for travelers who frequently travel between the U.S. and Canada and includes expedited crossings at land, marine and air borders.

By road, NEXUS members will find special lanes for their crossing that often have shorter lines than those available to the general public. Additionally, the questioning process at the border is often faster since their background check is already on file. When flying, NEXUS includes all TSA PreCheck and Global Entry benefits, as well as access to NEXUS kiosks when arriving in Canada (which works similarly to Global Entry when arriving in the U.S.).

NEXUS is duly-run by both nations, which means applicants will need to speak to border patrol officers from both countries as part of the interview and approval process. Like Global Entry, all ages must register for NEXUS if you travel as a family.

NEXUS is available at 17 U.S.-Canada land border crossings, typically coinciding with the busiest crossing ports in New York, Michigan and Washington (with a handful of other locations). If approved for NEXUS, you can also report your marine arrivals by phone rather than in person and avail yourself of TSA PreCheck, Global Entry and NEXUS kiosk locations when traveling by air.

CLEAR is a privately-run program that helps accelerate airport scans by using your fingerprints and your eyes instead of traditional ID. It doesn’t include TSA PreCheck, so it won’t help you skip taking off your shoes or removing your laptop and liquids from your bags at security. If you want the benefits of TSA PreCheck as well, you’ll need to enroll in TSA PreCheck as well as CLEAR. Many airports offer a separate CLEAR checkpoint for those with TSA PreCheck or funnel those with TSA PreCheck through to the correct security line. While CLEAR registration is limited to adults over 18, children can use the service when traveling with a registered adult.

At the moment, CLEAR is available at 45 airports in the U.S. If you love attending sporting events and concerts, CLEAR may also help you skip the line there as well. Many stadiums have begun using CLEAR as an alternative to traditional ID checks.