The acoustic guitar is a recognizable intrument. The classical guitar is mostly mistaken by this guitar but this guitar has a different head structure and you can also notice the difference on the bridge that is on the body of the guitar next to the hole carved into it. That hole is built in there to reflect the sound that the strings produce this makes the sound louder. The replacement for the strings between both guitars is different for the classical guitar you have to make a loop to tie on the strings. The acoustic guitar is more easier because it has little holes where you but the string in. The string should have a bead looking oblect attached to that helps it stay in the hole while you place a object in the hole so it can stay tight and the string doesn't come off.
This is a picture of a acoustic guitar and as you can see the strings are made out of steel and the head has a different structure.