Short answers, pulled from the story.
The Minotaur is a mythical creature from Greek mythology with the head and tail of a bull and the body of a man, also known as Asterion. He was the offspring of Pasiphaë, wife of King Minos of Crete, and a bull sent by Poseidon, and was confined in the Labyrinth designed by Daedalus near the palace at Knossos.
Athens was required to send fourteen young noble citizens, seven men and seven women, into the Labyrinth as sacrificial victims following Athens's defeat in a war with Minos. The tribute was punishment for the death of Minos's son Androgeus, whom the Athenians were held responsible for killing.
Theseus navigated the Labyrinth using a ball of thread given to him by Ariadne, daughter of King Minos, and killed the Minotaur according to various classical sources with his sword, a club, or his bare hands. He then led the surviving Athenians out of the Labyrinth and sailed away with Ariadne.
The name Minotaur derives from the Ancient Greek compound of Minos, the name of the Cretan king, and tauros, the word for bull. It translates literally as the bull of Minos. In Crete the creature was also called Asterion, meaning star.
In Canto 12 of Dante's Inferno, the Minotaur is called infamia di Creti, meaning the infamy of Crete, and serves as the first infernal guardian encountered within the walls of Dis. He represents the entire zone of Violence in the seventh circle of hell, in a role comparable to Geryon's role as the embodiment of Fraud.
Interpretations vary widely. Kerényi Károly argued the Minotaur was a luminous deity associated with stars and a Mistress of the Labyrinth goddess, supported by fifth-century coins from Knossos. Other scholars, including A. B. Cook and J. G. Frazer, proposed Minos and the Minotaur were two forms of the same sun-god. Some 19th century mythologists linked the Minotaur to the Phoenician Baal-Moloch, interpreting Theseus's victory as a memory of Athens ending its tributary relationship with Minoan Crete.