In the Package Manager window, when you select a feature set from the list on the left, the pane on the right displays details of the selected feature set. The details pane presents the contents of the feature set as a kind of miniature Package Manager window:
(A) When you select a feature set from the list view, its information appears in the details pane.
(B) The name and author of the feature set. The label always appears because feature sets are always matched to a specific version of the Editor and contain released packages that are supported for that version.
(C) A brief overview of the feature set’s purpose
(D) A link to the QuickStart guide for this feature set, containing details of how you can use this set of packages together
(E) An expander icon to toggle between showing and hiding the list of included packages and their details
(F) A button to Install or Remove the feature set.
Feature sets are collections of packages that work well together for a specific version of Unity, which means the Package Manager installs specific package versions that your feature set requires. However, there are a couple of reasons why the Package Manager might actually install a different version (override the requested version):
If the Package Manager installs a different version for any reason, an information message explains the reason for the change.