A grape is the non-climacteric fruit, botanically a true berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, … see full wiki
If you buy grapes, make sure they're seeded because grape seeds are one of the foulest-tasting things on the planet. The grapes themselves are nice and sweet, but I have to take points away for their lack of versatility. There's not a whole lot that can really be done with grapes unless you put them into the sun to turn them into raisins.