A Red Giant is a type of star that has exhausted the hydrogen fuel in its core and has expanded significantly in size. These stars are characterized by their reddish hue and large diameter, often becoming hundreds of times larger than the Sun. As they evolve, they undergo changes in temperature and luminosity, leading to a distinct phase in their life cycle. During the Red Giant phase, stars can shed their outer layers, creating beautiful nebulae, while the core contracts and heats up. Eventually, this process can lead to the formation of a White Dwarf or a more explosive end, depending on the star's mass.