A variation means a change or difference in something, or a version of something that's slightly different from the original. When you play the same song in a different key or tempo, you're creating a variation of it. When scientists study genetic variation, they're looking at the small differences that make each person unique, like eye color or height.

In music, composers often write variations on a theme, taking a simple melody and transforming it in creative ways: faster, slower, in a minor key, with different instruments. Mozart's famous variations on “Twinkle, Twinkle, Little Star” show how the same tune can become dozens of different pieces.

The word appears everywhere. A chef might make variations on a classic recipe, adding different spices or ingredients. Weather shows natural variation from day to day. Even your handwriting has slight variations each time you write the same letter.

Variation is closely related to variety, but there's a distinction: variation emphasizes the differences between similar things, while variety emphasizes having many different types of things. A garden might have great variety (roses, tulips, daisies), while each type of rose shows variation (slightly different shades of red or different numbers of petals).