The correct distinction is: Sarcasm says the opposite of what it means and is often used for ridicule.
While both sarcasm and verbal irony involve saying one thing and meaning another, sarcasm specifically carries a mocking tone and intention, often aimed at ridiculing or criticizing someone or something. Verbal irony, on the other hand, may not have that biting or scornful edge and can be used in a wider range of contexts, including humorous or playful situations without necessarily being mean-spirited.