This great article from Kitchn explains what cobblers, crumbles, and crisps have in common. They're baked fruit dishes topped with some kind of pastry. However, baked biscuits usually top cobblers. Crumbles and crisps are similar, each covered with a crumbly streusel-like topping. However, it used to be that oats were included in the topping and would make the dish crisp as it bakes. But often nowadays, people interchangeably use the terms "crumble" and "crisp."