Nitric Acid is an extremely useful chemical and one of the three most used mineral acids in any common lab (the others being Sulfuric Acid and Hydrochloric Acid). It can be used to produce nitrate salts and to nitrate organic compounds. It has some nice properties which are illustrated in another post.
It is usually available as a 68% solution (azeotropic concentration). Such solutions are usually referred to as Azeotropic Nitric Acid. Solutions of Nitric Acid with concentrations greater than 86% are referred to as Fuming Nitric Acid. The name comes from the fact that said solutions fumigate when an air stream is applied.