Delve into the intricacies of entanglement in Quantum Field Theory (QFT) and Quantum Gravity with this comprehensive lecture by Tom Hartman, part of the Kavli Asian Winter School on Strings, Particles and Cosmology. Explore key concepts including the path integral for SA, entropy, gravitational path integral, and ADS/CFT. Gain insights into important differences, potential instabilities, and semiclassical approximations in these advanced theoretical physics topics. Benefit from a detailed recap, in-depth explanations, and a concluding Q&A session to solidify understanding of these complex subjects at the forefront of high-energy physics research.