Wasps are neither a bee, nor an ant, but they share ancestry with both. In general wasps will react to perceived threat more aggressively than either bees or ants and their sting not only hurts, it can be deadly if you are allergic to their venom or are stung multiple times.
Wasps live in cracks and crevices, hanging from both natural and man made structures. They will also appropriate spaces in the ground like old rodent tunnels.
Hornets are a sub-species of Wasps. They tend to be larger, so their sting can pack a bigger punch.
Wasps and Hornets are pests you will want have removed from your home and/or property. Professional removal is highly recommended.