Fractals are geometric patterns that repeat at smaller scales through self-similarity. In programming, we create them using recursion—a function that calls itself with smaller inputs until reaching a base case (when order == 0, draw a straight line).

The Koch Snowflake replaces the middle third of each line segment with an equilateral triangle bump (turning left $60^\circ$, right $120^\circ$, left $60^\circ$). At each step the perimeter grows by $4/3$, yielding an infinite perimeter enclosed within a finite area!