Categories are big. Entire fields of mathematics can happen entirely inside a single category. But the study of categories themselves is more like algebra, and in many ways generalizes it. For example, a category with one object is a monoid. Categori cation is the opposite process — promoting an algebraic object to a category in such a way that its original structure can be recovered. I will explain a particularly neat way to categorify the Lie Algebra $\mathfrak{sl}(2)$ and its representations by means of pretty pictures.