In this talk, we review the notions of 2-group, Baez-Crans 2-vector space, and 2-representations of 2-groups. We will study the irreducible and indecomposable 2-representations, and finally we will show that for a finite 2-group $G$ and base field $k$ of characteristic zero, this theory essentially reduces to the representation theory of the first homotopy group of $G$.