Yes, indeed they are the same person, and just to confuse you more, he can also be known as Fernando Cortes. Although most people today know of him by the shortened version, Hernan Cortes.
Yes, they are, He can be known as Hernando, Hernan and even Fernando Cortes. Most people today know of him as Hernan Cortes. The spelling of Cortes with a z is wrong, he never spelt Cortes as Cortez...