The discovery of the Higgs boson in 2012 completed the Standard Model of particle physics, but many of its properties still need to be measured with high precision. Using the full dataset from Run 2 of the Large Hadron Collider, corresponding to proton–proton collisions at an energy of 13 TeV, the ATLAS experiment has carried out detailed studies of how the Higgs boson is produced and how it interacts with other particles. By combining results from many different decay channels, ATLAS achieves its most precise picture yet of the Higgs boson’s behaviour. These measurements test whether the Higgs behaves exactly as predicted by the Standard Model or whether there are hints of new physics. The seminar will also discuss studies of Higgs boson pair production, which probe the particle’s self-interaction and the shape of the Higgs potential. Finally, the results are interpreted in broader theoretical frameworks that explore possible extensions of the Standard Model.