Let us look at the Sun's resume. It is a middle aged star, at 4.5 billion years, and has 5 billion years more to live. It is a type G, yellow star, second or third generation, head of the Solar family. It is located in the Orion Arm of the Milky way galaxy.
How will the Sun die?
The sun is small, and will one day burn out all it's hydrogen supply. In the process of fusion, hydrogen is converted in to the heavier helium, and the extra proton mass is released as energy. Hydrogen, being lighter than helium, will rise to the outer layers, while helium will sink towards the centre. Eventually, the sun will run out of it's hydrogen, and start burning helium. When that ends as well, the outer layers will expand, and cool in the process. The star will become what is known as a Red Giant star. When the core collapses under it's own gravity, the outer layers and most of its mass will be shed in a beautiful display called a Planetary Nebula. The core will compress the helium at the center, and it will fuse to form carbon, which releases energy. At this stage, the star is a white dwarf. It is extremely dense, and slowly burns of its fuel, until it will slowly become a hunk of black nuclear matter floating in space.
This explanation can be better explained in a much more concise manner at
