Orcs are fictional humanoid creatures in J. R. R. Tolkien's Middle-earth legendarium. They appear in most of his Middle-earth stories, and are either the soldiers of the villain, or the villain themselves. They are also sometimes called goblins, as in The Hobbit.
Orcs were created by the Dark Lord Morgoth. Their exact origin is not certain, as Tolkien's idea of them evolved constantly. Among the possibilities are that they originate from Elves or Men, tortured and corrupted by sorcery, or cross-bred with evil creatures.
The Uruk-hai (Black Speech "Orc-folk") were a kind of orcs that appeared during the later part of the Third Age. The Uruks were larger and stronger than usual orcs. Saruman also created an army of Uruks for himself, who were also different in their higher tolerance for sunlight.
In The Hobbit, Bilbo Baggins and his Dwarven companions are captured by Goblins while crossing the Misty Mountains, but are rescued by Gandalf, who slays their leader. At the end of the book, the goblins have amassed a great army, which fights the protagonist's side at the Lonely Mountain, which became known as the Battle of Five Armies. In The Lord of the Rings, orcs appear as soldiers and henchmen of the Dark Lord Sauron and of Saruman.