Technical Numeric Prefixes

Standard Metric (SI) Prefixes, Values and Common Usage
There are many different size prefixes that are used to denote large and small numbers. The standard prefixes, from one trillion to one trillionth, are denoted below, along with some of the common places in the computer world where you will see them used:

Name	Abbr.	Decimal Power	Factor	Common Usage
tera	T	10^12	1,000,000,000,000	large data warehouses (TB)
giga	G	10^9	1,000,000,000	mass storage (GB), CPU speed (GHz)
mega	M	10^6	1,000,000	storage (MB), memory (MB), CPU speed (MHz), others
kilo	K	10^3	1,000	memory (KB), communication speed (KB/sec), others
milli	m	10^-3	0.001	drive access speed (ms)
micro	µ (Greek "mu")	10^-6	0.000001	various circuit speeds (us)
nano	n	10^-9	0.000000001	memory speed (ns), CPU cycle length (ns), capacitors (nF)
pico	p	10^-12	0.000000000001	capacitors (pF)