ADS-B is an acronym.
Automatic Dependent Surveillance-Broadcast (ADS-B)
https://www.faa.gov/nextgen/programs/adsb/
It is a Next-Generation aircraft collision avoidance system. It will be a required capability of almost all aircraft by the year 2020 (by FAA mandate)
Some people have seen this as an opportunity to get it installed early since it’s a great system to make the skies safer.
Because it works with a well-understood beacon signal that is sent out by your aircraft, the UAV/Drone industry has started to integrate electronics that use this technology to help drones avoid manned aircraft.
https://www.uavionix.com/products/pingrx/
I recommend getting started with Receive only capability so you can see how it works. It’s much more affordable, but the responsibility is on you to avoid manned aircraft since they won’t see you. You will need Transmit (ADS-B Out) and Receive (ADS-B In) so everyone can see you AND you can see everyone. 
https://www.uavionix.com/products/ping2020/
I hope this helps!
If you want to get excited about ADS-B, check this out:
https://www.flightradar24.com/
and the AR feature on this app:
https://itunes.apple.com/us/app/flightradar24-flight-tracker/id382233851?mt=8