There are many types of stars ranging from the very small and dense, to the very large and hot. All have different properties as well and are categorized into four main groups: dwarfs, giants, binary stars and neutron stars. Dwarf stars are classified in four groups: red, yellow, white and brown dwarfs. Red dwarfs are small, somewhat cool stars; yellow dwarfs are relatively small and not very hot, like our sun. These stars are very common throughout our universe. White dwarfs are small, very hot and very dense stars; their sizes are close to that of Earth. White dwarfs are mainly composed of carbon and are the remnants of a Red Giant that has lost its outer layers during the final stages of its life. Brown dwarfs are stars that do not have enough mass to continue nuclear fusion within the core.

There are three main categories of giants: red, blue and super-giants. A red giant is a star that has expanded from its original size in the last stages of its life. They become cooler and are usually orange in color. Blue giants are also very large and very massive, but unlike red giants, they are very hot as well. Super-giants are extremely large stars, sometimes the size of our solar system. These stars are rare in the universe and they die in the form of a cataclysmic explosion called a supernova and result in the formation of a black hole.