Quantifying isolated singularity in DEs

Consider a polynomial map $f: C^n\to C^n$, vanishing at some point $z_0$ in $C^n$. In differential equations, such points are called
equilibria of the vector field $z' = f(z)$, or their singular points. The question is "how singular". Can we quantify the singularity of $f$ at $z_0$?
Attempting only to demystify the problem, in this presentation we make an effort to quantify singularity in the sense of differential equations
and also discuss connections of this theory to analysis, topology and commutative algebra.