The title of the book Harry Potter and the philosoper's stone is appropriate -- why?

Answer 1

The original title of the book was "Harry Potter and the Philosopher's Stone". The US publisher thought that a US audience would not understand what a Philosopher's Stone was so asked to change it. J.K. Rowling choose the word Sorcerer.

A Sorcerer is a type of wizard, something the US audience would be familiar with, and that is somewhat relevant. Although the term sorcerer is never used to describe witches and wizards in the series.

She chose her title because the stone in the story is a "Philosopher's Stone" - it all makes sense then.

Answer 2

The title of the book, Harry Potter and the Philosopher's Stone is appropriate.

Even though the book is introducing the magic of wizarding world, and Hogwarts and everything. The main plot is about the trio (Harry Potter, Ron Weasley and Hermione Granger) finding out about 'The Philosopher's Stone' and trying to stop somebody, who they think is Severus Snape, trying to steal it.

That is the relevance of the title.