What type of star is the Sun classified as?

The Sun is classified as a G-type main-sequence star, often referred to as a G dwarf. This classification is based on its temperature, luminosity, and stage in the stellar evolution process. G-type stars have surface temperatures ranging from approximately 5,300 to 6,000 Kelvin, which is consistent with the Sun's temperature of about 5,500 Kelvin.

Main-sequence stars, like the Sun, are in a stable phase of stellar evolution where they fuse hydrogen into helium in their cores. This process produces a significant amount of energy, which is what makes the Sun shine and provides heat and light to the Solar System.

In contrast, red giants represent a later stage in the evolution of stars like the Sun, occurring after they exhaust their hydrogen fuel and expand. Blue supergiants are massive stars that have a much shorter life span and evolve rapidly through various stages. Lastly, white dwarfs are the remnants of low to intermediate mass stars after they have exhausted their nuclear fuel and shed their outer layers, marking the end stage of stellar evolution. The Sun is currently in the main-sequence phase, making the G-type main-sequence classification the correct one.