>>51497786OK, so I don't know shit about comp but this is what I can understand:
Competitive battling in the mainline pokemon games has 2 main formats: Smogon (created by a community of fans, usually single battles, more players iirc) and VGC (the official format, official vgc tournaments are held every year, double battles). Pokemon Showdown is a battle simulator and teambuilder, just like PvPoke. It's closely associated with and created by Smogon and although it does have a few VGC formats you can play on, most battle formats on it are Smogon ones. VGC players mostly play online within the game itself since it's officially supported whereas Smogon players tend to use showdown. You could play a Smogon match ingame but both players would have to have made an informal agreement to play by Smogon rules beforehand.