They are identical. It’s just a question of semantics. When someone tells me they are downloading at 96MBps I roll my eyes. It’s the 12MBps that matters to me and all that I look at. It’s a number I see day in and day out while the larger number is something I only see if I go to a place like Speedtest.
I *believe* that Speedtest uses Mbps because that is how ISPs advertise their speeds.