From The Lord of the Rings wiki
The Hobbit
The Hobbit is a fantasy novel by J.R.R. Tolkien that serves as a prequel to The Lord of the Rings, detailing Bilbo Baggins' unexpected journey to reclaim the Lonely Mountain from the dragon Smaug.
Overview
The Hobbit chronicles the quest of the hobbit Bilbo Baggins, who is recruited by the wizard Gandalf the Grey to assist a company of thirteen dwarves led by Thorin Oakenshield. Their objective is to recover the ancestral treasure of the dwarves, which has been seized by the dragon Smaug within the depths of the Lonely Mountain. The narrative follows their perilous trek across Middle-earth, encountering trolls, goblins, and wood-elves along the way.
Significance
This work is essential to the broader legendarium as it introduces the One Ring, which Bilbo discovers in the dark tunnels beneath the Misty Mountains after winning a riddle contest against the creature Gollum. The events of this journey establish the foundational lore for the subsequent conflict in The Lord of the Rings, highlighting the transformation of Bilbo from a timid homebody into a courageous adventurer. It remains a pivotal text for understanding the history and morality of the Third Age.