The Sun is a middle-aged yellow-white star.
Why it is true
The Sun is about 4.6 billion years old — approximately halfway through its expected life.
Source: NASA
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.