Dragonite is a Dragon- and Flying-Type, so it is weak against Rock-Types and Dragon-Types, and exceptionally weak against Ice-Types.
Dragon type moves are not very effective against Steel types. Dragon and Ice type moves are super effective against Dragon types.
It may sound weird but the only types weak against dragon Pokemon are other dragon Pokemon except ice types for some reason.
Water-Type moves are weak against Grass-Types, Dragon-Types, and other Water-Types. Water-Type Pokémon are weak against Electric-Types and Grass-Types.
Dragon type Pokemon are weak against Ice, Dragon, and Fairy type moves.
Garchomp is a Dragon- and Ground-Type, so it is weak against Dragon-Types and exceptionally weak against Ice-Types.
Dragonite is a Dragon- and Flying-Type, so it is weak against Rock-Types and Dragon-Types, and exceptionally weak against Ice-Types.
Dragon type moves are not very effective against Steel types. Dragon and Ice type moves are super effective against Dragon types.
It may sound weird but the only types weak against dragon Pokemon are other dragon Pokemon except ice types for some reason.
Water-Type moves are weak against Grass-Types, Dragon-Types, and other Water-Types. Water-Type Pokémon are weak against Electric-Types and Grass-Types.
Dragon type Pokemon are weak against Ice, Dragon, and Fairy type moves.
Dragon type moves are only super effective against Dragon type Pokemon.
Fairy-type Pokemon are weak against Poison and Steel-type attacks. Do not use Dragon-type attacks, for it is immune to Dragon.
Dragon-type Pokemon are weak against Ice, Dragon, and Fairy-type attacks, unless a dual-type adds or reduces weaknesses.
Dragon types(Garchomp, Haxorus etc) Ice types (Froslass, Weavile etc)
Kingdra is weak against dragon type moves.
Druddigon is weak against dragon and ice type pokemon