This thesis presents a series of studies on the evolution and out-of-equilibrium dynamics of strongly coupled quantum field theories by means of the AdS/CFT correspondence. We use a handful of analytic and semi-analytic techniques to investigate the response of the system due to different types of perturbations, some of them leading to thermalization, cooling down or coherent oscillations of the quantum fields. We characterize the processes by studying the evolution of non-local observables such as two-point functions, Wilson loops and entanglement entropy. Our results may be relevant to heavy-ion collision and condensed matter physics experiments.