A group or cluster of something is a bunch. It could be a bunch of people or a bunch of grapes. If you pick a bunch of bananas, you might end up being followed by a bunch of monkeys.
When you use the word bunch, you're generally talking about an approximate number of similar items, like a bunch of flowers or a bunch of cats or a bunch of your friends meeting for dinner. The verb bunch means "gather together," or "form into a bunch," the way you might bunch daisies together in a vase, or your socks might bunch down inside your boots.