Explore the intricate relationship between entanglement and theories of gravity in this 47-minute lecture by Suvrat Raju from the International Centre for Theoretical Sciences. Delve into key concepts such as Hilbert space, gauge-invariant operators in gravity, and the definition of entanglement entropy. Examine the puzzle surrounding local quantum field theory and investigate the distinction between coarse and fine entanglement. Learn about the Narnhofer & Thirring approach and an alternative definition of entanglement entropy. Conclude with a proof of the strong subadditivity (SSA) property and a thought-provoking conjecture. This talk, part of the Bangalore Area Strings Meeting 2017, offers valuable insights for string theorists, physicists, and researchers in quantum field theory and gravity.