The Fellowship of the Ring is the group of humans, hobbits, a dwarf and an elf that band together to help Frodo Baggins get to Doom Mountain in Mordor to destroy the One Ring that controls all other rings. The "leader" of the group is Aragorn, also known as Strider who turns out to be the King. The other humans in the fellowship is Gandalf the wizard and Boromir who is killed off at the end of LOTR - Fellowship of the Ring.
Non-human members of the fellowship includes Gimli, the Dwarf and Legolas Greenleaf, an elf who has a past that he's been running away from. The past was explained in Hobbit - Desolation of Smaug which is in the prequel trilogy to the Lord of the Rings.
By the end of the first film, the group splinters with Hobbits Samwise Gamgee sticking with Frodo who has decided to go it alone. The remaining Hobbits Peregrin -Pippin- Took and Merry stick with the rest of the fellowship.
Copyright: Tolkein Estates