Cisco APIC REST API

All of the configurable entities and their structure are represented as classes.
The classes define the entities that are instantiated as Managed Objects (MO) and stored within the Management Information Tree (MIT) - The concept is similar to the tree based hierarchy of a file system or the SNMP MIB tree.
All classes have a single parent, and may contain multiple children.
Each class has a name, which is made from the package and a class name, for example “top” is the package and “Root” is the class: “topRoot”; “fv” is the package (fabric virtualization) and “Tenant” is the class: “fvTenant”. A more generic form of this would be:

Package:classname == packageClassName

Managed objects make up the management information tree, and everything that can be configured in ACI is an object. MOs have relative names (Rn), which are built according to well-defined rules in the model. For the most part, the Rn is a prefix prepended to some naming properties, so for example the prefix for an fvTenant is “tn-“ and the naming property for a fvTenant would be the name, “Cisco”. Combining these gives an Rn of tn-Cisco for a particular MO. Relative names are unique within their namespace, meaning that within the local scope of an MO, there can only ever be one using that name. By using this rule paired with the tree-based hierarchy of the MIT, concatenate the relative names of objects to derive their Distinguished Name (Dn), providing a unique address in the MIT for a specific object. For example, an fvTenant is contained by polUni (Policy Universe), and polUni is contained by topRoot. Concatenating the Rns for each of these from top down yields a Dn of “uni/tn-Cisco”. Note that topRoot is always implied and does not appear in the Dn.

Reference: https://aci-troubleshooting-book.readthedocs.io/en/latest/index.html