yugioh, manga card game, got it. pokemon, video game anime, got it. digimon... tamagotchi anime?
yugioh monsters, projections of cards. pocket monsters, attack pets. digital monsters, like, from what I hear they've got essentially human-levels of intelligence?
I genuinely am having trouble discerning where the hook-on point for this, weird multimedia blob is? It's the anime, right? Because from the outside of having literally no interaction with the franchise over my life outside of like stray mentions in the context of specific contrast to pokemon, it looks like it's a franchise that kinda had a neat little toy, got an anime that hit, and then bumbled into literally every other industry that collectibles do and did them all in a way that made essentially zero cultural impact outside of unlimited contrarianism against pokemon by kids who had a chip on their shoulder about it.
all power to those kids in retrospect, good bit if that was the case, but it's something that's confounded me for a bit: have I been fucking hermetically-sealed off from a major cultural phenomenon? is this like an ozymandias situation where it's all ash in the present? is this just contrarian's pokemon as I thought it was when I was 12? I'm looking at the wikipedia page and my eyes are glazing over, it's like it's designed to be the most unintuitive thing for people who want to get a handle on it.
I don't get it 
The hook up is the anime, mostly talking about the first 4 series (adventure, 02, tamers, frontier) after that it had many breaks and it lost its momentum and unlike Pokemon it didnt have a big game to center its identity on since the many digimons games tried diferent things to see what sticks but that meant it didnt have a mainline game so it could keep getting popular.
it just kinda fumble on many things so it never capitalized on its early popularity hit like pokemon did with red and green