A tiled layer draws a set of web-accessible tiles that reside on a server. When the tiled web layer draws in ArcGIS Pro, a server request is made for the tiles needed to draw the layer at the current map extent and map scale. A tile layer can be used to draw a collection of tiles hosted at a known URL, or it can reference a cached map or image service.
The server does not recompute the map display. Instead, it retrieves the tiles for the appropriate map scale that have been precomputed and stored on the server. Only the images needed for display at the appropriate screen resolution are retrieved.
Tiled web layers are created at specific map scales. The scales for cached services are listed on the Source tab on the layer properties dialog box for the tiled web layer. In ArcGIS Pro, you are not restricted to these specific map scales. You can still zoom to any scale you want. However, since no new images are created by the server, ArcGIS Pro displays cached images from the closest available cache scale.
Get information on cached scales
The tiled web layer properties Source tab displays information such as the map extent, data (service) type, URL, service name, and default coordinate system of the service.
Navigate your map
As you pan, zoom, and navigate to any desired map scale, ArcGIS Pro displays the cached images closest to your display scale in your map.