Production companies??
 

I'm super confused tbh. All these names popping up like Endemol and Viacom, which is the one who did C4 and which is the one who did C5?

Viacom has just brought ch5 while endemol is a production company who owns the big brother franchise aswell as other things

Endemol is the production company

Viacom owns channel 5, they aren't producers.

Endemol is the company that has always owned BB, they produce the show, make the biggest majority of decisions and so on , the channel it's on now CH5 is now owned by Viacom, they lease the rights to air the show.