An Earth revolution is a trip around the sun in a closed path (relative to the sun).
The path is very nearly an ellipse with the sun at one focus, and a little less nearly a circle with the sun at the center.
One complete revolution takes roughly 365.24 days, and at that point, the Earth immediately begins another one.
We have a special word that we use to refer to that special period of time. In English, it's called a "year".
