According to docs.moodle.org article "Assign roles" the outermost context is known as the System context. It is confusing to see this context referred to in the Moodle user interface variously as "Global" and "Core system." The user interface terminology needs to be brought in line with the documentation.
I would suggest the following changes:
(1) change the link
:::: Site administration -> Users -> Permissions -> Assign Global roles
:::: Site administration -> Users -> Permissions -> Assign System roles
(2) change the heading
:::: Assign roles in Core system
:::: Assign System roles
(3) Review the help files linked to from the top of this page. They still treat Site and System as if they were the same thing.