CLEAR = biometric thing that checks your identity, letting you skip waiting in the line to show your ID to TSA. You still take off your shoes and empty your car

CLEAR = biometric thing that checks your identity, letting you skip waiting in the line to show your ID to TSA. You still take off your shoes and empty your carryon bag for the x-ray, you still go through the body scanner, but it gets you up to that point faster. TSA Pre = separate security line at airports which support it. Leave your shoes on, leave stuff in your bag, go through metal detector instead of body scanner. Basically the pre-9/11 airport security experience. Some airports which don't fully support Pre do various forms of relaxed rules for you when passing through an otherwise standard post-9/11 process. Global Entry = expedited passage through customs on entering the US. NEXUS = expedited passage through customs in both directions at the US/Canada border. Global Entry is likely the best value for money/effort, since it also gets you Pre, and also provides you with an ID card that you can use when crossing into the US by land, and use of an expedited lane at land crossings if you register your vehicle. NEXUS has similar benefits for US/Canada border and includes Pre, but is more difficult to obtain because you have to pass background checks from and interview with officers of both countries (CBSA and USCBP; Global Entry only requires check/interview with USCBP).