Precision measurements of vector boson production in associated with jets provide stringent tests of perturbative quantum chromodynamics (pQCD).
It allows a sensitive evaluation of the accuracy of pQCD predictions at the highest accessible energies and for a broad range of kinematic configurations
and allows to measure the Z invisible width at a hadron collider.
Total and differential cross sections of vector boson produced in association with jets have been measured using CMS data.
The W boson hadronic decay branching fraction ratio
$R_\mathrm{c}^\mathrm{W} = \mathcal{B}(\mathrm{W}\to\mathrm{c}\mathrm{q})/\mathcal{B}(\mathrm{W}\to\mathrm{q}\bar{\mathrm{q}}^{'})$
is measured with high precision at CMS thanks to the large cross section of top quark-antiquark production.