Because of irregularities in definition and usage of the kilobyte, the exact number could be any of the following:

1. 1 073 741 824 bytes - 1024 times 1024 times 1024, or 2³⁰. This is the definition used in computer science, computer programming and almost all computer operating systems.
2. 1 000 000 000 bytes or 10⁹ - this is the SI definition used by telecommunications engineers and some storage manufacturers.

A terabyte is equal to 1024 or 1000 gigabytes.

In speech, gigabyte is often abbreviated to gig, as in "This hard drive has 10 gigs". The initial G in giga- is usually pronounced hard as in girl, not soft as in giant. However, in the 1985 movie Back to the Future, the term giga was pronounced as jiga. A gigabit, which should not be confused with gigabyte, is 1/8th of a gigabyte and is mainly used to describe bandwidth, e.g. 2 gigabit/s is the speed of current Fibre Channel interfaces.

To clarify the meaning (1) above, the International Electrotechnical Commission (IEC), a standards body, in 1997 proposed short unions of the International System of Units (SI) prefixes with the word "binary." Thus meaning (1) would be called a gibibyte (GiB). This naming convention has not yet been widely accepted.

External links

• http://physics.nist.gov/cuu/Units/binary.html
• http://www.iec.ch/online_news/etech/arch_2003/etech_0503/focus.htm
• http://www.quinion.com/words/turnsofphrase/tp-kib1.htm
• http://www.nist.gov/public_affairs/techbeat/tb9903.htm