Complex sentence: Rep-tiles can be used to create fractals, or shapes that are self-similar at smaller and smaller scales, by subdividing, removing one or more copies of the subdivided shape, and then continuing recursively.
Split into simpler sentences: Rep-tiles can be used to create fractals, or shapes that are self-similar at smaller and smaller scales. A rep-tile fractal is formed by subdividing the rep-tile, removing one or more copies of the subdivided shape, and then continuing recursively.