Vouloir = literally: to want. It is a direct way express a desire or wish.Avoir envie de = "to have a desire for", "to be in the mood for something". L'envie means a wish, a desire or a longing.
Both mean very similar things but the latter is a less direct form to express a wish.
Sign in to submit your answer
Don't have an account yet? Join today
Test your French to the CEFR standard