Be Consistent with Terminology

The words (or copy) that you write in your product have a dual purpose. The first is the most obvious: they label items and views and tell the user which elements are which.

The second is less obvious, but more important: the words you use become a very precise and descriptive language for your product. Understanding and parsing this language is essential to a user forming a mental model of how your product works.

• If you call your e-commerce shopping cart a “cart,” then call it “cart” everywhere
• If you call your user’s profile page “profile,” then call it “profile” everywhere
• If you call your user’s email settings “email settings,” then call them “email settings” everywhere

Mix these up and it will take your user longer to ponder the inconsistent terms and work out what you mean.

Think also about the tone of voice...