Measurements of the production of the electroweak bosons pairs $WW$ and $WZ$ have been performed in proton-proton collisions at $\sqrt{s}=13\,\mathrm{TeV}$, using $36.1\,\mathrm{fb}^{-1}$ of data collected by the ATLAS experiment at the Large Hadron Collider. Detector-level distributions and unfolded differential cross sections have been measured and compared to theoretical predictions at high order in perturbative QCD (up to next-to-next-to-leading order). The results of the $WW$ analysis were interpreted in terms of an Effective Field Theory to constrain anomalous triple gauge couplings, while those from the $WZ$ analysis enabled the determination of the $W$ and $Z$ polarizations for the first time from diboson events in hadronic collisions.