What's the difference between PNP, PNP+iStone, BNF, SRTF?

[Aydın Cam]

I'm a novice rc aircraft enthusiast,so I want to know What's the difference between PNP, PNP+iStone, BNF, SRTF?

[Oscar]

PNP - Plug and Play.  A plane without Receiver, Transmitter, Battery
PNP+iStone - Basically its Plug and Play with a Gyro stabilizer. You have to provide your own Receiver, Transmitter and Battery. (Manufacturer like Dynam RC model uses iStone Gyro stabilizer)
BNF - Bind and Fly.  A plane comes with Receiver (some manufacturers like Horizon Hobby their Receiver will include the Gyro called AS3X and Stabilizer)
SRTF - Smart Ready To Fly - A plane comes with Receiver, Transmitter, Battery, Charger (Not all model comes with Gyro Stabilizer). 

[Michael]

PNP - Plug and Play.  Your plane will need a Receiver, Transmitter and Battery before you can crash it.
PNP+iStone - Basically its Plug and Play with a Gyro stabilizer. You still have to provide your own Receiver, Transmitter and Battery before you can crash it.
BNF - Bind and Fly.  A plane comes with Receiver, that must be bound to a transmitter, so you have to provide your own Transmitter and Battery before you can crash it.
SRTF - Smart Ready To Fly - A plane comes with Receiver, Transmitter, Battery, and Charger. Completely ready to crash.