Choosing Between an Electric and Acoustic Guitar when Starting Your Guitar Lessons

The reason for the different cased letters and the apostrophe over the e, is to differentiate between the different E’s, A’s etc that the guitar is able to play, this is known as Helmholtz notation. To put it another way, imagine a piano, an E at one end of the key board will sound quite different to an E at the other end so Helmholtz notation is one way of telling them apart when written down.