During the recent decades, space missions (e.g., CHAMP, GOCE, GRACE and Swarm) have been developed by space agencies in Europe and the USA to measure the Earths gravity and magnetic fields and their spatio-temporal variations. These successful missions have already provided a wealth of groundbreaking results about the permanent and time-variable gravity and magnetic fields of the Earth. However, more can be learned about the Earths structure by combining data of the gravity and magnetic fields, together with Earths rotation data routinely measured using space geodesy techniques, as well as with the most up-to-date modelling of the Earth's internal structure. Use in synergy of these global observables and model data represents a unique way to further investigate the physics of the deep Earth's interior. In addition to the well-known correlation between Earths rotation and magnetic field observed at interannual and decadal time scales, recent studies have reported unexpected correlation between spatio-temporal changes of the gravity field and magnetic field, also at interannual time scale. These changes may result from processes occurring in the liquid core and at the core-mantle boundary. This book gathers a series of chapters that provide state-of-the art overviews on the gravity field, magnetic field and Earths rotation observations, and on their interpretation in terms of the deep Earths structure, as well as on core dynamics and processes at the core-mantle boundary. The chapters 'Gravity Variations and Ground Deformations Resulting from Core Dynamics', 'Rapid Variations of Earths Core Magnetic Field', 'A Dynamical Prospective on Interannual Geomagnetic Field Changes', 'Core Eigenmodes and their Impact on the Earths Rotation', 'Earths Rotation: Observations and Relation to Deep Interior', 'Interiors of Earth-Like Planets and Satellites of the Solar System', 'Correction to: Interiors of Earth-like planets and satellites of the Solar System', 'Fluid Dynamics Experiments for Planetary Interiors', 'Structure, Materials and Processes in the Earths Core and Mantle', 'Correction to: Structure, Materials and Processes in the Earths Core and Mantle' and 'Applications and Challenges of GRACE and GRACE Follow-On Satellite Gravimetry' are available open access under a Creative Commons Attribution 4.0 International License via link.springer.com. Previously published in Surveys in Geophysics, Volume 43, Issue 1, 2022.