PnP / RR Stands For Plug & Play / Receiver Ready
Typically these Aircraft are electric powered and require minimal assembly. Most have Motor, Electronic speed controller (ESC), and Servos pre-installed but do require your own Transmitter (TX), Receiver (RX), and flight battery pack and charger to complete.

ARTF Stands For Almost Ready to Fly
These Aircraft can be either Glow Engine (Nitro) (IC) or Electric powered (EP). They can be either balsa wood construction or foam construction and require assemble. Most will require multiple items to complete including Engines or Motors all radio servos and batteries.