  We introduce the gauge/gravity, or AdS/CFT, correspondence with an eye
towards its application to strongly coupled systems. We provide an overview of
the duality, including the AdS/CFT dictionary and holographic renormalization.
We then discuss simple correlation functions in the context of renormalization
group flow geometries, holographic thermodynamics and an application to the
phase diagram of QCD, real-time correlators and the shear viscosity of strongly
coupled field theories, holographic superconductors, and the application of
holographic fermionic response to strange metals. These lectures were delivered
at TASI 2017.
