Introduction.- Methods & Concepts.- Cosymmetries.- Codimension One.- Transcritical Bifurcation.- Poincar e-Andronov-Hopf Bifurcation.- Application: Decoupling in Networks.- Application: Oscillatory Profiles.- Codimension Two.- egenerate Transcritical Bifurcation.- egenerate Andronov-Hopf Bifurcation.- Bogdanov-Takens Bifurcation.- Zero-Hopf Bifurcation.- Double-Hopf Bifurcation.- Application: Cosmological Models.- Application: Planar Fluid Flow.- Beyond Codimension Two.- Codimension-One Manifolds of Equilibria.- Summary & Outlook.