YANG
Yet Another Next Generation (YANG) is a data modeling language for the definition of data sent over network management protocols. It is a tool that is used to define a more "human-friendly" modeling language for defining the semantics of operationla data, configuration data, notifications, and operations.
It acts as a method of simplification, or an additional layer of abstraction that makes communication using protocols such as NETCONF more user and human friendly.
Links
https://networklessons.com/cisco/evolving-technologies/data-models-and-structures
https://networklessons.com/cisco/evolving-technologies/device-programmability