Earth is an alternate version of the Realverse's Earth, found in the Fantendoverse. It is the home of many temporal anomalies, due to the influence of Corner and Nava (time travelers who originated from Earth in different timelines).
Corner's Alpha Timeline
Corner's Alpha Timeline is considered the "original" timeline of Earth. In this timeline, Corner did not invent his time machine until the age of 50, at which point he traveled to the first instance of Corner's Beta Timeline and delivered the time machine to himself.
Corner's Beta Timeline
Corner's Beta Timeline is a timeline with a near infinite number of variants, caused by the stable time loop created by Alpha!Corner. At the age of 50, Beta!Corner travels to a new variant of the Beta Timeline and delivers the time machine to himself. This repeats infinitely, with only minor or no differences expressing themselves between variants except in the case of the Anomaly timelines.
A number of anomalies exist within the Beta timeline variants. These are timelines which, although they do not interrupt the time loop, are for whatever reason vastly different to the other timelines within the loop.
Corner's Omega Timeline, despite being different to the other Beta timelines, is not considered an anomaly as it is the end of the loop rather than an anomaly within it.
Corner's Omega Timeline
Corner's Omega Timeline is the "main" timeline, and the origin of the version of Corner who exists in the Fantendoverse (Omega!Corner). It's difference to the other variants of the Beta timeline is the presence of Nava. Her rivalry with Corner drastically changes his actions from those the Beta!Corner's took, and eventually leads to the end of the time loop and the creation of Nava's Alpha Timeline.
Nava's Alpha Timeline is the origin timeline of Nava, created by the actions of Omega!Corner sometime in the future. Rather than deliver the time machine to Beta!Corner, as all other Beta!Corner's had done, Omega!Corner instead delivered the time machine to Nava, allowing her influence on him in the past to lead him to giving her the time machine in the first place.
It is unknown what event sparked the initial difference in Corner's Omega Timeline which allowed the creation of Nava's Alpha Timeline and the major differences to emerge through Nava's interaction.