The Sun is very BIG compared to the Earth. Over a
million Earths could fit inside the Sun. Or you could line up
over 100 Earths across its middle. However, compared to
other stars, our Sun is only a medium-sized star, meaning
that some stars are much larger than the Sun and some are
much smaller.
The Sun looks bigger than other stars because it is so
much closer to the Earth. The further away an object is, the
smaller it appears, even if it is very big.