Definition: Kbps

(KiloBits or KiloBytes per SECond) One thousand 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, Mbps and Gbps.

Kilobits - "b" (Kbps, Kb/sec, Kb/s)
Kilobits per second is used to rate serial data transmission devices such as analog modems.

Kilobytes - "B" (KB/sec, KB/sec, KB/s)
Kilobytes per second is used to rate parallel data transfers such as from memory to disk in early computers.