Squashes are a broad family of vegetables which are the botanical fruits of the Cucurbita genus. This makes them part of the gourd family, and they are often just called “gourds” themselves. However, you don’t have to care about the botanical specificities. One notable type of squash is the pumpkin, which is typically referred to separately.
Squashes are eaten in a variety of ways. Often they are just cubed, cooked, and served with little else or in a vegetable medley; but they are also commonly made into casseroles, pies, and soups. They’re never eaten raw. They’re often mildly sweet but not especially so. They are much more starchy than they are juicy.
Thus, as squashes exhibit the traits of a vegetable, they are vegetables, regardless of their botanical classification. (Technically, they’re botanically berries even!) They also grow very close to the ground just are culturally recognized as vegetables, which is what matters for words.