Severus Snape is a complex and multifaceted character in the Harry Potter series. He serves as the Potions Master and later the Defense Against the Dark Arts professor at Hogwarts School of Witchcraft and Wizardry. Initially portrayed as a villain, Snape's true loyalty and motivations are revealed later in the series. He is characterized by his deep, unrequited love for Lily Potter, Harry's mother, which shapes many of his actions throughout the story. Snape's role is pivotal, influencing the narrative and contributing to the ultimate defeat of Lord Voldemort.