  In the paper we introduce and study a classification of finite (simple,
undirected, loopless) graphs with respect to a switch-equivalence
(`local-complement' equivalence of \cite{pascvebl}, an analogue of the
complement-equivalence of \cite{conell}). In the paper we propose a simple
inductive method to compute the number of switch-types of graphs on $n$
vertices and we show that there are exactly 16 such types of graphs on 6
vertices.
