Model Builder in ArcGIS allows users to visually create, edit, and run geospatial models. It provides an interface for stringing together geoprocessing tools, datasets, and other elements in a workflow. Key benefits of Model Builder include simplifying complex workflows, enabling easy reproduction of analyses, and automating repetitive tasks. The visual programming environment in Model Builder allows non-scripting users to leverage the power of geoprocessing tools without writing code. Models can be run, edited, and shared with others to streamline common GIS tasks.