Verified answer

All stars, including the Sun (note the "the" and the capital "S" for the Sun... no it is NOT called Sol, in the English language, outside of science fiction writing) go through an impressive nuclear process.

Fusion.

What happens inside the Sun (or any star) is atoms combining together to form heavier atoms (but fewer of them) and the release of a lot of energy (heat and light).

The Sun is still in "main sequence" stage of its life. It is fusing mostly Hydrogen (4 atoms) into (1) Helium (atom... + that energy I mentioned above).

Eventually, the Sun will run low on hydrogen, to the point where it will need to fuse a heavier element... Hydrogen. At that point in time, because of gravity, mass, and thermonuclear equilibrium, the Sun will cool down (surface temperature) and expand, several solar radii... about the toe orbit of Earth.

This will be in about 5 billion years, when the Sun becomes what is called a Red Giant.

Almost all main sequence stars go through this phase.

But the one thing that all stars have in common, is the fusion aspect of this equation. More massive stars run through their Hydrogne supply faster, less massive ones, like Red Dwarfs, live on the main sequence for (possibly) trillions of years, fusing hydrogen very slowly, because they have such low massescompared to other stars.

Our sun has always been a star. Evey twinkily thing in the naght sky is both a sun and a star (except for the satellites)

And technicly, the sun isn't called the Sun.

It's called Sol.

There are lots of stars in the universe. We the star in our solar system 'the sun'. It's the same as having planets and 'Earth, Mars,etc.'

Yes the sun is a star....and there is not how just a start....Is the closest star to our planet, we belong to the set of planets of the sun(the solar system). the next closest star to us is 4 light years away.

Yes the sun is a star, why? Well its just like asking because your friend is diffrent in looks to you how does it make him human there is no how it just is.

Because the Sun is a massive, luminous ball of plasma that is held together by gravity.

It's like asking: "Is Obama human? how?"