Grand Theft Auto: Roleplay
RP is the abbreviation for roleplay. This means that players put themselves in the shoes of another character who lives in the virtual world. This virtual world does not know the real world, which means that information you have obtained outside the game may not be used by you in the game. The character is created and then played by the player himself.
The whole thing is done in the game Grand Theft Auto - a quite realistic game which offers a good basis for this. GTA Roleplay (GTARP for short) is one reason why the game GTA V is still a popular title several years after its release.