https://www.youtube.com/watch?v=A22oy8dFjqc&feature=youtu.be&t=6m50s

Listen, I've been playing guitars for almost 6 years and trust me, acoustic guitars are not classical guitars. The body material changes, the strings are different and the fretboard width and thickness do change too! These two types of guitars are easily recognizible one from each other. Acoustic means that while playing you transmit the strings' vibrational energy to the air in order to make a sound. There also exist electric acoustic guitars. Those are simple acoustic guitars with a pickup inside the body and a battery slot so that you can plug it to an amplification set.