In The Lord of the Rings, Bilbo Baggins’s sword is named Sting.
Bilbo finds Sting, along with the swords Glamdring and Orcrist, in the trolls’ hoard during The Hobbit. Although it is a small sword for a human, it is an effective blade for a hobbit. Its distinctive property is that it glows blue when orcs are nearby.
Bilbo later gives Sting to Frodo before Frodo leaves the Shire. Frodo carries it through much of his journey, including the passage through Moria and the confrontation with Shelob. Samwise Gamgee also uses Sting after rescuing Frodo from the tower of Cirith Ungol.
Andúril is a different sword: Aragorn’s reforged blade. Glamdring belongs to Gandalf, while Orcrist is the sword Thorin Oakenshield carries in The Hobbit. Those similar names are a frequent source of confusion.