Music is and has been a huge part of most cultures around the world, and in many types of music the guitar plays an important role in creating and molding the sound and style of the music. Of course different types of guitars are used for different sounds and styles, and one quite common and popular type of guitars used is the acoustic guitars.
Acoustic guitars get their name from the type of amplification that they provide. Unlike electric guitars, it don't need external devices in order to form proper amplification, they are amplified acoustically. But the acoustic amplification provided by the Acoustic guitars does not produce a loud sound, so sometimes external devices are used to help amplify the its sound. It was the only type of guitars until electric guitars were created.