Sharp

Sharp (wikipedia)

means higher in pitch. More specifically, in musical notation, sharp means "higher in pitch by a semitone (half step)," and has an associated symbol (♯), which is often confused with the number (hash) sign (#). The key difference is that the number sign has compulsory true horizontal strokes while the sharp sign cannot have them. Instead, the sharp sign has two slanted parallel lines which rise from left-to-right. Both signs may have true-vertical lines; however, these are compulsory in the sharp, but optional in the number sign (#) depending on typeface or handwriting style.

provided by http://en.wikipedia.org/wiki/Sharp_(music)