Basics

An Abbreviation for Real Time Kinematic Satellite Navigation
Essentially Satellite Navigation but more precise
This is done via a basestation sending correction data to the moving componet, known as the "rover unit"
Many rovers can use one base station See this post on how to do this effectively
All in all this can produce anywhere from centimeter to single didgit milimeter accuracy depending the setup
VERY useful for RC and Autonomous Vehicle Applications
Also used for surveying
Basestations can be a service for larger scale, or purchased/built and placed/operated by the user

Electronics