  We give an introduction to the Quantum Spectral Curve in AdS/CFT. This is an
integrability-based framework which provides the exact spectrum of planar N = 4
super Yang-Mills theory (and of the dual string model) in terms of a solution
of a Riemann-Hilbert problem for a finite set of functions. We review the
underlying QQ relations starting from simple spin chain examples, and describe
the special features arising for AdS/CFT. We also discuss the recently found
links between the Quantum Spectral Curve and the computation of correlation
functions. To appear in a special issue of J Phys A based on lectures given at
the Young Researchers Integrability School and Workshop 2018.
