^ another episode to remember is TNG Paralells. It confirmed a multi verse existed in star trek. Where variations of reality existed. In comics parallel worlds are create by making different decisions, time travel effects, and or things not working out the way they did in the timeline we follow. Such as the two Ent-D's where Riker was captain but Picafs was killed in BOBW, and another where Captain Riker failed at BOBW and the Borg won and Riker refused to go back to his universe
If you tried to keep it all straight. Every time travel incursion or every variation of history (like Picars saying FC with the Klngons led to decades of war but with ENT we never saw Archer engage in a war after FC with ghe Klingons. You would go mad. Thing is this can be very confusing even in comic book world. What most writers do is never dwell on the fact they've created parallel worlds. Once back in their correct time no matter what time effects may have happened. That timeline is treated like it has always BEEN the original. Until DC or Marvel feels like doing a big epic like Crisis on Infinite Earth's, Infinite Crisis or Countdown to destruction, there is never an explanation for the variations. Partially explains how so many different writers can tackle different comic characters and yet not all their stories match up in one continuous timeline.