A kettlebell is a cast-iron or steel weight shaped like a ball with a single handle on top. It is used for strength training, cardiovascular conditioning, and functional fitness. The unique design allows for swinging, lifting, and pressing movements that engage multiple muscle groups at once. Kettlebells help improve strength, endurance, balance, flexibility, and coordination. They are commonly used in exercises such as swings, goblet squats, cleans, and snatches, making them suitable for both beginners and advanced fitness enthusiasts.