Reference
Web map specification
The Web Map Specification describes the JSON object which defines a web map.
Web scene specification
The Web Scene Specification describes the JSON object which defines a web scene.
Arcade
Arcade is a portable, lightweight, and secure expression language written for use in the ArcGIS platform.
Spatial reference WKIDs
Geographic and vertical coordinate system tables
Spatial references
Learn how to use different coordinate systems, such as WGS84 and Web Mercator.
Distance and area units
Distance and area unit tables
Map view zoom levels and scale
Learn how zoom levels relate to scales.