What is the mathematical basis of fractals?

A fractal is a geometric shape that when zoomed in on, will look approximately the same as it did before. Fractal geometry is a more complex version of regular Euclidean geometry. Euclidean geometry included just circles, squares, triangles, hexagons, octagons and all other regular shapes. Fractal geometry is the study of fractals and all of its components. Fractal geometry, out of all of its other uses, is mainly used to describe every other shape possible that isn’t classified into regular Euclidean geometry. Although not many people know what a fractal is, they encounter them on a regular basis and fractals have many uses all of which are extremely overlooked by many people.