The topological properties of isolated singularities of complex spaces of codimension one

The article is devoted to a comparison of the topological properties of a nonsingular model $\overline V_s$ of a complex surface $V_s$ with isolated singularities and a nonsingular surface $V_t$ in the same family of surfaces. This is done by the introduction of a relation of partial ordering and of equivalence relation in the set of isolated singularities defined by one equation $\mathbf C^n$.