In this picture of a quilt, there is a larger circle surrounding a smaller one. Since these circles have the same center, they are examples of concentric circles.
Quilt #3 by Carrie Severt. Photo by Lyntha Scott Eiler, Blue Ridge Folklife Project, American Folklife Center, Library of Congress.
A dart board demonstrates examples of concentric circles.
Each circle in the target has the same center - the bull's eye.