Definition

global account creation: for wikis with centralauth enabled, which includes all production WMF-hosted wikis, this is a "regular" account creation
local account creation: a special case account created only on a specific wiki
Event Platform: https://wikitech.wikimedia.org/wiki/Event_Platform
Approximate: Events sent via Event Platform are not 100% guaranteed, but the loss is minimal and especially minimal in well-defined flows like account creation (if events are lost, they're usually lost due to very complex page renders taking longer than the global kill timer).

Account Registrations Metric: Approximate weekly count of global account creations, only on Wikipedias, grouped by mobile/desktop, project family, and the English Name of the wiki.

Data Source: event.serversideaccountcreation