Self-similarity is a concept where a shape or pattern looks similar at different scales. For example, if you zoom in on a fractal, like the Mandelbrot set, you will see that the smaller parts resemble the whole. This means that no matter how much you magnify it, the pattern remains consistent, creating a fascinating visual effect. This idea can also be found in nature, such as in trees and snowflakes. A tree's branches split into smaller branches that look like the entire tree, while snowflakes have intricate designs that repeat at smaller sizes. Self-similarity helps us understand complex structures in both mathematics and the natural world.