Layers provide visualization capabilities for data hosted in Feature Services, Map Services and Image Services. See Introduction to Layer Types for more information on when to use which type.
Tasks are wrappers for commonly used API methods on ArcGIS services. They expose commonly used parameters to make them more accessible to Leaflet.
Utility classes helpful for making AJAX requests to ArcGIS Server and ArcGIS Online and manipulating responses.
The classes below provide the underpinnings for
Layers classes which are typically added to maps. Services wrap ArcGIS API endpoints exposing common methods for interacting with the APIs and handling proxying and authentication.