Simply put, the more tightly the strings are wound, the higher the pitch. Each string is tightened to a specific tension so that when it is strummed or plucked, a specific note is the result. In an acoustic guitar the sound is amplified by the hollowness of the guitar's body. With an electric guitar the vibrations created when the string is plucked are collected by the guitar's pick ups ( they "pick up" the sound waves) and deliver them through the amplifier.

