  Models with extended Higgs boson sectors are of prime importance for
investigating the mechanism of electroweak symmetry breaking for Higgs decays
into four fermions and for Higgs-production in association with a vector
bosons. In the framework of the Two-Higgs-Doublet Model using two scenarios
obtained from the experimental measurements we presented next-to-leading-order
results on the four-fermion decays of light CP-even Higgs boson, $h \rightarrow
4f$. With the help of Monte Carlo program Prophecy 4f 3.0, we calculated the
values $\Gamma= \Gamma_{EW} /\left(\Gamma_{EW}+\Gamma_{SM}\right)$ and $\Gamma=
\Gamma_{EW+QCD} /\left(\Gamma_{EW+QCD}+\Gamma_{SM}\right)$ for Higgs boson
decay channels $ H \rightarrow \nu_{\mu} \overline{\mu} e \overline{\nu_e}$,
$\mu \overline{\mu} e \overline{e}$, $e \overline{e} e \overline{e}$. We didn't
find significant difference when accounting QCD corrections to EW processes in
the decay modes of Higgs boson. Using computer programs Pythia 8.2 and
FeynHiggs we calculated the following values: $\sigma(VBH)BR(H\rightarrow ZZ)$
and $\sigma(VBF)BR(H \rightarrow WW)$ for VBF production processes,
$\sigma(ggH)BR(H \rightarrow WW)$ and $\sigma(ggH)BR(H \rightarrow ZZ)$ for
gluon fusion production process at 13 and 14 TeV and found good agreement with
experimental data.
