A difference is what makes two or more things not exactly the same. When you compare your favorite pizza toppings with your best friend's, the difference might be that you love pepperoni while they prefer mushrooms. When you subtract one number from another in math, you find the difference between them: the difference between 10 and 7 is 3.

Differences can be tiny or enormous. The difference between identical twins might be a small birthmark, while the difference between a bicycle and an airplane is massive. Sometimes differences matter a lot (the difference between a winning and losing score), and sometimes they barely matter at all (the difference between two shades of blue paint).

People often say “it makes no difference” when something doesn't change the outcome or when they don't care which option is chosen. If someone asks whether you want to meet at 3:00 or 3:15, you might say “it makes no difference to me.”

The phrase “make a difference” means to have a real impact or effect. When you help a younger student understand their homework, you're making a difference in their learning. When a scientist discovers a new medicine, they make a difference in people's health. Small acts of kindness can make a surprising difference in someone's day.