An exoplanet (exo-planet), is an extra-solar (outside of our solar system) planet orbiting a star, other than the Sun, within our Milky Way galaxy.
The Kepler Telescope mission has discovered 4,000+ confirmed exoplanets in all, as of February 2015.
by DaleBryTheScienceGuy February 23, 2016
Many planets (over 200) have been discovered in the nineties that don't go around our Sun. They are exoplanets.
by darksongbird April 02, 2009