Global vs Site Term Set

Global terms can be used across multiple sites. When this is leveraged, the first site to use the term set becomes the parent where all profiles are managed. Appropriate permissions need to be applied to the parent site to ensure people profiles can be accessed from other sites.

Global terms should be used where cross site reporting and term consistency can be leveraged.

Site terms should be used when terms are unique to the site contents, for example in training areas, where content may be targeted to people based on course groupings or topics.