The bodog group has a long history of corporate restructuring - mainly a consequence of trying to operate in different unregulated to gray area markets at the same time with questionable legal status, but apparently there were some weird shifts and ownership transfers going on years before the UIGEA (2006) even existed in the USA, so there may have been other reasons as well. There have been multiple instances of the entire player base (mainly of the USA) essentially being forcefully migrated to a new domain name - and then the "new" owner basically denying shared ownership.
So at first it was mainly just bodog, known for their sports book and later poker platforms. U.S. players then had their accounts migrated to bovada and were locked out of the main bodog site. Then, a couple years later, bovada locked USA players out of the poker room and migrated over to ignition (but the casino/sportsbook may have remained open to U.S. players? Not 100% sure). But about a year after that, Bovada reopened completely to U.S. players.
So now it's something like bodog serves canada, ignition serves U.S. and australia, and bovada serves U.S. and latin america. Those sites all operate on the same poker network with shared player pool and tables. Then they also opened up the more casino focused sites slots.lv and cafecasino.lv at some point - I'm not 100% sure what the situation with those two sites are, if they're actually run any differently from the main sites with the poker rooms. So the sites are obviously all connected, but the couple times I've asked about the status of an account they've denied any connection to the other websites.
Edit: I might have it backwards that the main bodog sites serves latin american countries + Canada while bovada serves U.S. + Mexico? Well, you get the idea anyway. There's also apparently a bodog88 site targetting the chinese market.