Map image, imagery, and elevation layers are prerendered collections of map cartography organized by location and scale. Imagery and map image layers can be displayed dynamically or as cached image tiles. Elevation layers are cached services that contain Limited Error Raster Compression (LERC) imagery.
Dynamic layers generate images when requested by the client viewing the layer. As you browse the map, new map images are generated and displayed. Dynamic map layers include map services and image services. Map services are based on vector data, which is typically a combination of points, lines, and polygons of geographic features. One common use of a map service is to show business data on top of a basemap tileset. Image services are based on raster data, which is essentially a grid of cells. Rasters are commonly used to store imagery and other information captured by satellite sensors.
Cached layers are organized collections of image tiles for specific geographic extents, projections, and levels of detail that are pregenerated on a server. Cached map layers include cached map services and cached image services. Cached layers support fast visualization of complex maps, since the server distributes the images whenever someone asks for a map. These map layers are created and stored on the server after you upload your data. They are appropriate for basemaps that give your maps geographic context.
For more information on publishing the map services and image services that populate map image, elevation, and imagery layers that you can add to Map Viewer or Scene Viewer, or add as an item to My Content, see the following topics in the ArcGIS Pro help: