Rechargeable nickel-metal hydride (NiMH) batteries are a type of rechargeable battery that uses nickel and hydrogen to store energy. They are commonly used in various devices, such as digital cameras, remote controls, and electric vehicles, due to their ability to hold a significant charge and provide reliable power. NiMH batteries are known for their higher energy density compared to traditional nickel-cadmium (NiCd) batteries, which allows them to store more energy in a smaller size. They are also less harmful to the environment, as they do not contain toxic metals like cadmium. However, they can self-discharge more quickly than other battery types, requiring more frequent recharging.