The API calls are like function calls, you make a single function call and pass parameters. Seeing how it's an API format, it could be used on a number of things, not only network devices.
https://pubs.opengroup.org/onlinepubs/9629399/chap6.htm

https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r7-
0/programmability/configuration/guide/b-programmability-cg-asr9000-70x/b-programmability-cg- asr9000-70x_chapter_011.html

users?
Explanation:
https://developer.cisco.com/docs/sdwan/#!device-realtime-monitoring/users API call for real-time monitoring of users logged in to the device.
Device Users
Display the users currently logged in to the device.
GET https://{vmanage-ip-address}/dataservice/device/users?deviceId=deviceId

Zero touch provisioning (ZTP)
Explanation:
https://developer.cisco.com/docs/ios-xe/#!day-zero-provisioning-quick-start-guide

The correct module to use for managing Layer 3 interfaces (such as loopbacks) on Cisco IOS XE devices in an Ansible playbook is . This module allows configuration or deletion of L3 interfaces using structured data, as shown in the playbook. The state deleted ios_l3_interfaces along with a list of interface names is a valid use case for ios_l3_interfaces.