Definition: Mbps

(MegaBits or MegaBytes per SECond) One million bits or bytes per second. The correct abbreviation is "b" for bits and "B" for bytes; however, "b" and "B" are often erroneously interchanged. See space/time, Kbps and Gbps.

Megabits - "b" (Mbps, Mb/sec, Mb/s)
Megabits per second is used to rate serial data transmission such as Ethernet, Wi-Fi and USB.

Megabytes - "B" (MBps, MB/sec, MB/s)
Megabytes per second is used to rate parallel data transfers such as from memory to disk.