Data transfer speed is expressed in bits. In bit rates the abbreviations are as follows:

• 1 kbps = 1,000 bits per second
• 1 Mbps = 1,000,000 bits per second.
• 1 Gbps = 1,000,000,000 bits per second.

kbps (kilobits/sec) means thousands of bits per second
mbps or Mbps (megabits/sec) means millions of bits per second
gbps or Gbps (gigabits/sec) means billions of bits per second (where "billion"= 1,000,000,000.00")
tbps (terabits/sec) means trillions of bits per second (as in "terabit router" or "terabit speeds")
pbps (petabits/sec) means quadrillions of bits per second. (where do I sign up?)

Filesize (the size a file is on your computer)is usually measured in units of "kilobytes,""megabytes," and "gigabytes."

In this computing (binary, but not data transfer) usage, 'K'(uppercase) represents a multiplier of 1,024.
Other abbreviations use this same base of 1,024:

• 1 KB (one KiloByte) = 1,024 Bytes (approximately 1 thousand Bytes)
• 1 MB (one MegaByte) = 1,024 KB (approximately 1 million Bytes)
• 1 GB (one GigaByte) = 1,024 MB (approximately 1 billion Bytes)