image tile package
An image tile package is a read-only data file containing static, pre-rendered image tiles. It can be created from an image tile service, or by ArcGIS Pro. It is often used in offline applications that never have a network connection, but can also be used as a local basemap by an offline map. Image tile packages are used by applications built with ArcGIS Maps SDKs for Native Apps. There are two file formats for an image tile package: TPKX and TPK. Both TPKX and TPK are supported by Native Maps SDKs and ArcGIS Pro. TPKX follows the Open Tile Package Specification.