This section contains information about "complete" vehicles that can PX4. It lists ready-to-use commercial vehicles, drone "platforms" on which you might base your own development, and kits that you can use to assemble an unmanned vehicle from parts.
# Fully Assembled (PX4 Preinstalled)
This section lists vehicles that are sold fully assembled and ready to fly (RTF), with PX4 installed.
# Fully Assembled (PX4 Compatible)
This section lists fully assembled vehicles where you can update the software to run PX4.
# Drone Development Kits/Reference Platforms
This section lists drone kits that are intended as platforms for further development. They may come either fully assembled or in parts.
# UAV Kits
This section list kits that contains all the parts needed for building a PX4-compatible vehicle (with the possible exception of batteries and RC controllers).
Kits provide a gentler introduction to building drones than starting from individual components. They allow you to use parts that are known to work, and to fly a vehicle that is appropriately tuned.
# Fully Assembled (Custom PX4)
This section contains consumer vehicles that run a custom version of PX4 (supported by their vendors). These may or may not be updatable to run "vanilla" PX4.