  These lecture notes review the theoretical background to the Higgs boson,
provide an introduction to its phenomenology, and describe the experimental
tests that lead us to think that "beyond any reasonable doubt, it is a Higgs
boson". Motivations for expecting new physics beyond the Standard Model are
recalled, and the Standard Model effective field theory is advocated as a tool
to help search for it. The phenomenology of $N = 1$ and $N = 2$ supersymmetric
Higgs bosons is reviewed, and the prospects for possible future Higgs factories
are previewed.
