Durin's Folk :

Dates: Durin the Deathless awoke during the Years of the Trees after the awakening of the Elves.
Race: Dwarves.
Settlements: Historically, the main seat of this Folk was at Khazad-d�m.
Other Names: Folk of Durin and Longbeards.
The Dwarves descended from Durin the Deathless,eldest of the seven Fathers of the Dwarves.Almost all of the Dwarves that appear in Tolkien's works are of this Folk.
Longbeards :
One of the seven clans of the Dwarves,those that were descended from the oldest of the Seven Fathers of the Dwarves,Durin the Deathless.This people is more commonly known as Durin's Folk.
Petty Dwarves :

Dates: Originated during the Years of the Trees.The last Petty-dwarf was killed in about I 500.
Origins: Exiles from the eastern Dwarf-cities.
Race: Originally Dwarves.
Other Names: Nibin-Nogrim,Noegyth Nibin.
A small,stunted people,apparently related to the true Dwarves,who died out in Middle-earth in the late First Age.
All information is thanks to the Encyclopedia of Arda and the Annals of Arda.
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