This is such a common confusion, someone made a handy diagram for telling apart the firms comprising the cross product of {"Black", "Bridge"} x {"rock", "water", "stone"}.
Correction to the minor correction, Blackrock, the asset manager/ETF provider, does not engage in institutional purchasing of SFH homes. For a little while BlackStone, the Private Equity firm, had an ownership interest in company that did this, but I’m not sure they still do.
https://i.redd.it/x0jeiofl7j471.jpg