Edition of pokes

Hi,


I wanted to ask what r editions of pokemon eg : 1st and 2nd , and is there a 3rd edition.



Does it mean that pokes with 1st edition r better than pokes of 2nd edition ?







And is necrozma legendary poke or ultra beast ( cause in sun and moon its a legendary type poke and not UB so i was wondering if it can be caught without beast ball )



Please help.

Thanks!



I didn't find the right solution from the Internet.



References:
 forums.pokemon-vortex.com/topic/8526-edition-of-pokes/

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