What is the purpose of YANG?

YANG (Yet Another Next Generation) is a data modeling language used to define the structure and constraints of configuration data, state data, RPCs (Remote Procedure Calls), and notifications for network devices. It provides a standardized, human-readable way to describe the data models that can be manipulated by network management protocols like NETCONF and RESTCONF. This standardization allows for automation and programmatic interaction with network devices, moving beyond vendor-specific CLIs. Scraping data via CLI is an ad-hoc, error-prone method, not a purpose of YANG. Processing SNMP read-only polls is a function of SNMP, a different protocol, and while YANG can model SNMP MIBs, its primary purpose isn't processing polls. Providing a transport for network configuration data is the role of protocols like NETCONF or RESTCONF; YANG defines the content being transported, not the transport mechanism itself.