Use the noun salon when you talk about the place you get your hair cut. A salon is a good place to get a perm or highlights, to get your nails painted, or just to get a trim.
A salon is like a barber shop, only fancier. Most salons offer all kinds of beauty treatments in addition to haircuts, like hair styling and coloring, facials, and massages. Another kind of salon is a formal living room — if you invited guests for tea, you might sit and sip it in your salon. The word salon is French, originally meaning "reception room." In 1800's France, the meaning grew to include a "gathering of elegant people" occurring regularly in such a room.