When Voldemort and his followers refer to Muggle-borns, werewolves, or anyone else who wouldn’t be considered a Pureblood wizard, they call them “diseased branches of the family tree” or “weeds.” Why does Rowling utilize these descriptions?

Some characters show bravery in unconventional ways in Harry Potter. How does Hermione show bravery throughout the novel?

Many beloved characters die in The Deathly Hallows. Why are these deaths necessary? How do they contribute to the themes of the story?