its or M
ytes per SEC
ond) One million bits or bytes per second. Mbps is a measurement of peripheral data transfer or network transmission speed. The correct abbreviation is "b" for bits and "B" for bytes; however, "b" and "B" are often interchanged. See space/time
Lower case "b" - Mbps, Mb/sec, Mb/s
Megabits per second is used to rate serial data transmission such as Ethernet and Wi-Fi.
Upper case "B" - MB/sec, MB/s
Megabytes per second is used to rate parallel data transfers such as from memory to disk.