Re: Is there a diference between a parallel universe and alternate tim
. "Parallels" introduced the concept of "quantum signatures", which were unique to each timeline and were used to match Worf with his Enterprise (it also shows us a branching "Y" diagram). Yes, IRL the signature, if expressed numerically, would be as complex as pi, but notheless it's part of Star Trek's canon.
I'll also point out that if the Star Trek multiverse were made up of preexisting universes, there would be endless paradoxes (like how does STXI timeline exist if the allies only won WWII due to the interference of Kirk, Spock and McCoy in "City on the Edge of Forever"? What about the Roswell Incident? Transparent Aluminum? Spock's maturity test?), none of which exist in a branching multiverse. We've seen alternates of Braxton, Spock, Picard, Janeway, Daniels and whatnot moving down the endless timeline tree and shifting us onto new paths.
WRONG! At least for Star Trek's worldTemis the Vorta said:You can never know if you are travelling in time, across dimensions, or both.

I'll also point out that if the Star Trek multiverse were made up of preexisting universes, there would be endless paradoxes (like how does STXI timeline exist if the allies only won WWII due to the interference of Kirk, Spock and McCoy in "City on the Edge of Forever"? What about the Roswell Incident? Transparent Aluminum? Spock's maturity test?), none of which exist in a branching multiverse. We've seen alternates of Braxton, Spock, Picard, Janeway, Daniels and whatnot moving down the endless timeline tree and shifting us onto new paths.