  The paper reminds the basic ideas of stochastic calculus via regularizations
in Banach spaces and its applications to the study of strict solutions of
Kolmogorov path dependent equations associated with "windows" of diffusion
processes. One makes the link between the Banach space approach and the so
called functional stochastic calculus. When no strict solutions are available
one describes the notion of strong-viscosity solution which alternative (in
infinite dimension) to the classical notion of viscosity solution.
