from
The Collaborative International Dictionary of English v.0.48
Micro- \Mi"cro-\, Micr- \Mi"cr-\ . [Gr. mikro`s small.]
A combining form signifying:
(a) Small, little, trivial, slight; as, microcosm,
microscope.
(b) (Metric System, Elec., Mech., etc.) A millionth part of;
as, microfarad, microohm, micrometer.
[1913 Webster]
from
Jargon File (4.4.4, 14 Aug 2003)
micro-
pref.
1. Very small; this is the root of its use as a quantifier prefix.
2. A quantifier prefix, calling for multiplication by 10^-6 (see
{quantifiers}). Neither of these uses is peculiar to hackers, but
hackers tend to fling them both around rather more freely than is
countenanced in standard English. It is recorded, for example, that
one CS professor used to characterize the standard length of his
lectures as a microcentury -- that is, about 52.6 minutes (see also
{attoparsec}, {nanoacre}, and especially {microfortnight}).
3. Personal or human-scale -- that is, capable of being maintained or
comprehended or manipulated by one human being. This sense is
generalized from microcomputer, and is esp. used in contrast with
macro- (the corresponding Greek prefix meaning `large').
4. Local as opposed to global (or {macro-}). Thus a hacker might say
that buying a smaller car to reduce pollution only solves a
microproblem; the macroproblem of getting to work might be better
solved by using mass transit, moving to within walking distance, or
(best of all) telecommuting.
from
The Free On-line Dictionary of Computing (8 July 2008)
prefix
atto-
exa-
femto-
giga-
kilo-
mega-
micro-
milli-
peta-
pico-
tera-
yocto-
yotta-
zepto
zetta-
1. <unit> The standard metric prefixes used in the {Système
International d'Units} (SI) conventions for scientific
measurement.
Here are the SI magnifying prefixes, along with the
corresponding binary interpretations in common use:
prefix abr decimal binary
yocto- 1000^-8
zepto- 1000^-7
atto- 1000^-6
femto- f 1000^-5
pico- p 1000^-4
nano- n 1000^-3
micro- * 1000^-2 * Abbreviation: Greek mu
milli- m 1000^-1
kilo- k 1000^1 1024^1 = 2^10 = 1,024
mega- M 1000^2 1024^2 = 2^20 = 1,048,576
giga- G 1000^3 1024^3 = 2^30 = 1,073,741,824
tera- T 1000^4 1024^4 = 2^40 = 1,099,511,627,776
peta- 1000^5 1024^5 = 2^50 = 1,125,899,906,842,624
exa- 1000^6 1024^6 = 2^60 = 1,152,921,504,606,846,976
zetta- 1000^7 1024^7 = 2^70 = 1,180,591,620,717,411,303,424
yotta- 1000^8 1024^8 = 2^80 = 1,208,925,819,614,629,174,706,176
"Femto" and "atto" derive not from Greek but from Danish.
The abbreviated forms of these prefixes are common in
electronics and physics.
When used with bytes of storage, these prefixes usually denote
multiplication by powers of 1024 = 2^10 (K, M, and G are
common in computing). Thus "MB" stands for megabytes (2^20
bytes). This common practice goes against the edicts of the
{BIPM} who deprecate the use of these prefixes for powers of
two. The formal SI prefix for 1000 is lower case "k"; some,
including this dictionary, use this strictly, reserving upper
case "K" for multiplication by 1024 (KB is thus "kilobytes").
Also, in data transfer rates the prefixes stand for powers of
ten so, for example, 28.8 kb/s means 28,800 bits per second.
The unit is often dropped so one may talk of "a 40K salary"
(40000 dollars) or "2 meg of disk space" (2*2^20 bytes).
The accepted pronunciation of the initial G of "giga-" is
hard, /gi'ga/.
Confusing 1000 and 1024 (or other powers of 2 and 10 close in
magnitude) - for example, describing a memory in units of 500K
or 524K instead of 512K - is a sure sign of the {marketroid}.
For example, 3.5" {microfloppies} are often described as
storing "1.44 MB". In fact, this is completely specious. The
correct size is 1440 KB = 1440 * 1024 = 1474560 bytes. Alas,
this point is probably lost on the world forever.
In 1993, hacker Morgan Burke proposed, to general approval on
{Usenet}, the following additional prefixes: groucho (10^-30),
harpo (10^-27), harpi (10^27), grouchi (10^30). This would
leave the prefixes zeppo-, gummo-, and chico- available for
future expansion. Sadly, there is little immediate prospect
that Mr. Burke's eminently sensible proposal will be ratified.
2. <language> Related to the {prefix notation}.
(2003-05-06)