As a result of Lord Voldemort’s weakened state, the dark wizard attempts to gain possession of the heavily guarded philosopher’s stone, a magical item that would restore his health. The philosopher’s stone is based on the mythical item of the same name that was said to be able to turn ordinary metals into gold and also produce and elixir of life that would ultimately delay death.
The philosopher’s stone was renamed the sorcerer’s stone in American version of the book and movie because the publishers thought that many American readers would not be familiar with the story or properties of the philosopher’s stone, so they tried to make the story more appealing by changing the title.