Deference and Difference are easily confused words. The spell-check of most word processing software programs would not catch a slip-up among these three words. As long as it’s a word and it is spelled correctly, spell-check keeps on scanning the document.
Deference is a noun. It means behavior that shows dutifulness and consideration of a superior’s point of view.
Difference is a noun usually referring to a point of comparison of two or more things sizes, qualities, volumes, etc. It means the opposite of similarity. In math, the difference is also the answer that results from subtracting one number from another.
The following sentence uses both words correctly:
Sonia noticed a significant difference in new employee attitudes at work: while Delilah showed her utmost deference in issues great and small, Desmond was more of an independent thinker.