A beehive is a structure — either made by humans or bees — in which bees live and make honey. You might find a beehive in a hollow tree.
If you become a beekeeper, you will either build or buy one or more beehives for your bees to live in. You might wear a protective suit, with a hat and netting that covers your face, when you are cleaning or checking on your beehives, to avoid being stung. Around 1960, the word beehive began being used to refer to a remarkable hairstyle, a round, high teased style that requires plenty of hairspray.