Tera-

teras- (symbol: T) is a prefix in the SI system of units denoting 10¹², or 1,000,000,000,000 (1 trillion).

Confirmed in 1960, it comes from the Greek τέρας, meaning "monster". [ [http://www.yourdictionary.com/ahd/t/t0112100.html YourDictionary.com] , "tera-", Retrieved on 2007-06-05.] It also bears a resemblance to the Greek prefix τετρα- meaning "four"; the coincidence of it signifying the fourth power of 1000 served as a model for the higher-order prefixes peta-, exa-, zetta- and yotta-, all of which are deliberately distorted forms of the Latin or Greek roots for the corresponding powers (fifth to eighth respectively) of 1,000.

In computer science tera- can sometimes mean 1,099,511,627,776 (2⁴⁰) instead of 1,000,000,000,000, especially in the term terabyte. To avoid this ambiguity, the binary prefix tebi- has been introduced to signify 2⁴⁰, but this, in common with the other binary prefixes, is not currently in general use.

References

ee also

*SI prefix
*Binary prefix
*ap|Tera