Quantum Many Body Systems are at the basis of many Quantum Simulations. It is therefore of upmost interest to understand their information content and structure and how it can be manipulated and extracted or measured. One avenue, based on our understanding of quantum field theories, is based on correlation functions, which reveal the accessible structure and their effective descriptions either directly or through learning algorithms. A different approach is through many-body tomography which then allows to extract of von Neuman entropies. This allowed us to verify the area law for mutual information in quantum many body systems. The tomography approach is limited to Gaussian effective models. Currently we are developing new model agnostic approaches, which allows to study also strongly correlated and topological systems. Finally, I will ask the question what it takes to erase information in a many-body system and present our experiments probing Landauer's principle in the quantum many-body regime.