  The Higgs boson was discovered by the ATLAS and CMS Collaborations in 2012
using data from Run 1 of the Large Hadron Collider (2010$-$2012). In Run 2
(2015$-$2018), about 140 fb$^{-1}$ of proton$-$proton collisions at a
centre-of-mass energy of 13 TeV were collected by the ATLAS experiment. This
review presents the most important Run 2 results obtained by the ATLAS
Collaboration regarding the properties of the Higgs boson and its interactions
with other particles. The performed studies significantly enhance the
understanding of the Higgs boson, while hunting for deviations from the
predictions of the Standard Model of particle physics.
