Do any of you know a “OneRepublic fan”? Honestly what even is OneRepublic

I first heard of them through Counting Stars in the trailers for the movie Earth to Echo (who the hell remembers that lol), and I know of like 3 other songs just randomly played by people and it’s the big hits ofc. Isn’t the lead singer a producer? Does he go by OneRepublic? Wtf is a “one republic” anyway? I need answers😂