>>716249883There's four.
Arcade DK is Cranky Kong, Main DK's grandfather.
Arcade DK Jr. is Main DK's father.
Main DK is the one we see in Mario games and the DKC series. The DK games happen before the Mario games.
Main DK Jr. is Main DK's son. He doesn't exist yet in the DK games, but he exists by the time of the Mario games. He's the character we see in GB Donkey Kong, Super Mario Kart and Mario Tennis 64.
Arcade DK kidnapped Lady (the grandmother of Pauline) and was defeated by Jumpman (whose real name is Mario, but he's the grandfather of the Mario we know). Jumpman then kidnapped Arcade DK and was defeated by Arcade DK Jr. This was such a sensational event that it became the foundation of New Donk City.
Two generations later, Main DK's adventures in his own series happen. He's about Mario's age (see Yoshi's Island DS) and both are older than Pauline by a few years (as she's only 13 by the time of Bananza).
Later on, Main DK has a son (Main DK Jr.), Tiny Kong grows up as well, and we're in the era of the Mario games. Main DK's first interaction with Mario as an adult is in GB Donkey Kong: he gets excited seeing Pauline again, takes her with him as with the good old times, but he's an idiot so he doesn't realize she doesn't want that. Her boyfriend, Mario, chases Main DK around the world and defeats him. They become friendly rivals after that, and Main DK shows up at sports and party events. At some point the Mario vs. Donkey Kong games also happen.
We know DK kidnaps Lady and is defeated by Jumpman before New Donk City is founded because that's literally said to be the foundational event of the city in Mario Odyssey. We also know Pauline got kidnapped by DK and rescued by Mario because she brings it up in the same game. Her being a teenager in Bananza while New Donk City already exists only works if Arcade Donkey Kong and GB Donkey Kong are two separate events with separate people. And Bananza hints at this by implying that Pauline's grandmother is Lady.