There is only one Sun in the Solar System, which is the 9 planets that revolve around our Sun. The sun, however, is just one ordinary and insignificant second-generation (which means it is made up of materials that came from previously exploded stars) star in a hundred billion in our Milky Way Galaxy, and there are billions more in the other galaxies that make up the universe. If you look up on the clearest of clear nights, every twinkle you see is a star burning the same fuel as our Sun, and for every one you can see there are billions that you can't.
There are 9 planets including Pluto. Most authorities no longer consider Pluto to be one of the major planets.
To help understand this question, the approved definition of a Star being a Sun is "A star that is the center of a planetary system." or "any star around which a planetary system revolves" Therefore, all Suns are Stars, but not all Stars are Suns.