Alternate Timeline

Not to be confused with an Alternate Universe, a difference in setting from the original universe.

An Alternate Timeline is a different series of events that unraveled in the history of the franchise. Present day of this Alternate Timeline can be the results of a certain event happening, what the world would be if an event didn't occurred, or if the outcomes of an occurrence (a war, personal experience, agreement, etc.) were played out differently from the first timeline. The only sensible way to access an Alternate Timeline within a franchise's canon is Time Travel which itself isn't plausible if the right conditions aren't met.