Pretty much everyone using Mac or iOS has an iCloud Email account. Apple allows three Aliases to be added to your main iCloud Email. Why would you need an Alias? You would use an Alias in any situation where you did not want your main iCloud Email out in the open. That might be a shopping website or perhaps signing up for a specific service online. Creating an Alias on your iCloud account is a bit convoluted, but doable. This article explains how to do it.