What is boba?
The short answer: they're cassava starch balls.
The longer answer: the term boba can, holistically, be in reference to the entire drink-plus-toppings, the most popular topping being tapioca pearls (which also happen to be called boba -- I know, it's confusing, but stay with me!). The drink as a whole is also known as bubble tea, pearl tea, and tapioca tea -- depending on what part of the country you're from. As stated earlier, the tapioca pearls that are also called "boba" are generally made from cassava starch, a root vegetable from South America that is also referred to as yuca.
Boba -- the drink in its entirety -- originates from Taiwan, though its disputed which city and specific shop it actually started from. Originally, boba pearls were used in shaved ice desserts and paired with syrups, beans, and delectably chewy rice balls. Milk tea was also consumed regularly and thankfully, someone decided to merge the two, thus creating the genius, beloved drink we now have today.
Boba culture made its way to America through Taiwanese neighborhoods and blossomed near college campuses and high schools, where students would gather for study groups. Most boba shops, even now, are open late and offer affordable snacks and drinks -- which made them the perfect stop for late-night hang outs and crunchtime studying.