Monitoring the land surface and its changes over time is essential for updating and maintaining regional and global reference frames, as they require accurate plate kinematics and deformation models to remain consistent over time. Elevation models are necessary for producing accurate topography maps, contour lines, and elevation profiles, providing the basis for national, regional, and global topographic databases. These databases are essential for orthorectifying satellite images and creating 3D visualizations to extract terrain features and to facilitate land use and land cover classification. They also support river flow modelling and drainage analysis, flood risk assessment and simulation of inundation zones, as well as management of irrigation and water resources. They are also useful for planning radio tower placement, signal coverage, and satellite communications as well as for simulating line-of-sight and interference zones. Terrain models are mandatory to model topography gravity signals in order to improve the accuracy and resolution of the geoid. Horizontal deformation models enable the monitoring of plate tectonics, rift zones, and subduction processes, as well as the detection of fault movements, strain accumulation, and post-seismic deformation. Vertical deformation models are essential for detecting ground subsidence due to groundwater extraction, mining, or oil/gas withdrawal, monitoring uplift from glacial isostatic adjustment, tectonic activity or mountain building, as well as for determining movements induced by glacier melting and permafrost. Vertical land motion estimates in coastal areas are fundamental to measuring relative sea level change for the planning of coastal zone management and climate change adaptation/mitigation. The following geodetic products are key to realising, monitoring and applying this Essential Geodetic Variable: