Shavuot falls after a verbal counting of the 49 days between the Jewish holidays of Passover and today – the formal end of the counting of the Omer (the days between Passover and Shavuot). It is the milestone day the Israelites received and accepted the Torah at Mt. Sinai.
We celebrate the day by eating dairy products like cheesecake, blintzes, kugel, and staying up all night to study and learn (tikkun) our history. If lactose intolerant, there are many vegan alternatives out there, so one can still celebrate with tofu, oat milk or almond milk “dairy.”