In geoprocessing in ArcGIS, a tool and its parameter values. One process, or multiple processes connected together, creates a model.
An ArcGIS Image Server operation applied to a specific raster dataset or the data in an image service. A process can modify the radiometry, geometry, or appearance of an image. Examples of ArcGIS Image Server processes include Blend Pixels, NDVI, and Stretching.
In ArcGIS Image Server, applied to an image service definition or each raster within the image service definition.