Contemporary unified gauge models of the electroweak interaction contain not only quarks, leptons, and intermediate vector bosons, but also elementary spinless fields, whose inclusion is essential for renormalizability of the theory--the so-called Higgs bosons. A large class of problems related to the Higgs bosons is considered. The greatest attention is devoted to the Weinberg–Salam model, in which there is one such boson. The characteristics of this boson are discussed in detail: the coupling constants are fixed, and bounds on the mass are given. Theoretical estimates are given for its production cross sections, lifetime, and relative probabilities of decays into different channels. Various generalizations of the model with a greater number of Higgs particles are considered. A brief review is given of closely related questions: the hypothesis of ``grand unification'', classical solutions of the Polyakov--'t Hooft monopole type, and axions. A special section is devoted to an alternative variant in which no elementary Higgs fields are introduced (the so-called ``Technicolor'' scheme).