who is snape in relation to harry potter
Severus Snape Severus Snape is a fictional character in J. K. Rowling's Harry Potter series. An exceptionally skilful wizard, his coldly sarcastic and controlled exterior conceals deep emotions and anguish. A Professor at Hogwarts School of Witchcraft and Wizardry, Snape is hostile to the series' protagonist, Harry, the moment he sets foot in Snape's classroom; this hostility is rooted in Harry's resemblance to Harry's father James, who bullied and harassed Snape during their time at Hogwarts. Though philosophically attracted to the Dark Arts and Lord Voldemort's ideology of wizard supremacy, Snape's love for Muggle-born Lily Evans, Harry's mother, eventually compels him to defect from the Death Eaters. Snape becomes a double-agent on behalf of Albus Dumbledore and the Order of the Phoenix, and protects Harry throughout the series.
Harry Potter and the Half-Blood Prince (film) Dumbledore instructs Harry to hide and not to interfere no matter what happens. Draco arrives in the Astronomy Tower and disarms Dumbledore revealing that he has been chosen by Voldemort to kill the headmaster. When Draco is unable to bring himself to do it, Snape casts the killing curse instead, killing Dumbledore, who falls from the tower. Harry confronts and attacks Snape, but Snape overpowers him, and reveals himself as the Half-Blood Prince before escaping. Harry returns to Hogwarts, where the students, staff, and a few guests mourn Dumbledore's death. Harry later reveals to Ron and Hermione that the locket Horcrux was a fake. The locket contains a message from "R.A.B.", stating that he has stolen the real Horcrux with the intent of destroying it. Rather than returning for their final year at Hogwarts, the three decide to hold out, and track down the remaining Horcruxes.