The Sun is a star.
Stars appear much fainter because they are much further away.
The distance to the nearest stars was found in the mid-18th century using parallax. The Earth's orbit acted as the baseline, so a star had to be observed at different times of the year. This is the standard distance measurement to stars. A star with a parallax of 0.1 arcsecs is 10 parsecs away. Another unit of distance measure is the lightyear, the distance light travels in a single year.