There is some debate over whether or not “backup” is one word or two. The Oxford English Dictionary lists it as two words, but many people treat it as one word.
There are a few reasons why people might think that “backup” is one word. The first reason is that the word “back” is often used as a prefix meaning “backward.” For example, the word “backward” means “moving or going in the opposite direction.” So the word “backup” might be …
