The vSphere Automation Tag Service supports the definition of tags that you can associate with vSphere objects or vSphere Automation resources.
Starting with vSphere 6.5, the vSphere Automation APIs provide programmatic access to creating and managing vSphere tags in your vSphere inventory.
For example, if you want to tag your virtual machines by guest operating system type, you can create a category called operating system. You can specify that it applies to virtual machines only and that only a single tag can be applied to a virtual machines at any time. This category can include the following tags: Windows, Linux, and Mac OS.