Harry doesn't have a family—well, he does, but they're kind of awful—and he comes to Hogwart's basically alone in the world. A big part of Harry Potter and the Sorcerer's Stone entails him not only learning about the mother and father he lost, but finding his own family—a better family—at Hogwarts.
His friends Ron and Hermione quickly become like siblings, while Dumbledore and McGonagall act like surrogate parents. He even gets a snotty little cousin in Draco Malfoy, and Snape plays that uncle who gives everybody the creeps at Thanksgiving.
Hey, it beats living in that cubbyhole under the stairs, right?
Questions About Family
How do the parental circumstances of the three main characters define them?
How do the Houses—and Hogwarts in general—help serve as family for the students there?
How do Harry's dead parents help him? How do they hinder him?
Are the Dursleys really Harry's family? If not, then who is, and why?
Chew on This
Family is fate in the Potterverse: the death of Harry's parents determines his future.
Family is a matter a choice, determined by whom you trust rather than whom you're related to.