To vary means to change or to be different. When you vary your routine, you do things in a different order or try new activities instead of doing the same thing every day. A chef might vary the ingredients in a recipe to create different flavors, or a teacher might vary the types of assignments to keep the class interesting.

Things can also vary from each other, meaning they're different in some way. The houses on your street might vary in size and color. Students' opinions about the best pizza topping vary widely: some love pepperoni, others prefer mushrooms, and still others like pineapple (which starts arguments).

The word suggests difference with purpose or pattern. When a musician varies the tempo of a song, they're making deliberate changes to create interest. When test scores vary across a classroom, they show a range of results. Scientists pay close attention to what varies in their experiments because those changes help reveal important patterns.

The related word variety means having many different kinds of something, while various means several different kinds. If you eat various fruits for variety, you're varying your diet. When something stays exactly the same without any changes, we might say it's invariable or that it doesn't vary at all.