How big will your a account get. Remember you might want Bill Gates as a customer. One of the simplest uses of a group of bits is fixed point numbers and character data. I will look at character representations first. Now we will look at characters.
Many standards exist for representing characters on computer systems.
You could invent your own until computers started being networked. They also fail to cover extensions. Character sets are remarkably arbitrary. As long as everyone agrees, it works great. England has problems.