The term wasp is for any insect member of the order Hymenoptera, suborder Apocrita, most of which are stinging. Wasps can be distinguished from the bees and ants of Apocrita by several physical and behavioral characteristics.
With so many different species buzzing around, it is almost impossible to tell wasps apart by size. Some of them are less than half an inch, while others can grow up to 1.6 inches (Asian giant hornets).
Generally speaking, wasps are less hairy than bees because they are not primarily pollinators like bees. When bees fly from one flower to another, they use their body hair to collect pollen which is later stored.