petabyte

petabyte - noun - One quadrillion (10 to the 15th power) bytes

I found this word in this wonderful email signature:

"Peta" is Greek for fifth; a petabyte is 10 to the fifth power, as
well as fifth in line after kilo, mega, giga, and tera.

However notice the mistake: 10^5 is 100000 which is less than mega, quite a bit less than giga and a huge amount less than tera. The correct reference should have been 1000^5. Interestingly, since we deal in powers of 2 (binary) for digital computers, the actual number of a petabyte is 1024^5 (2^50) or 1,125,899,906,842,624. Given the discrepancy between 1000^5 and 2^50, it has been suggested that petabyte be equal to 1000^5 while pebibyte be equal to 2^50, but this isn't widely used. In reality, most people probably don't know what comes after terabyte anyway.

Here is some extra history about the prefix 'Peta' which is interesting:
Adopted in 1975, it comes from the Greek πέντε, meaning five, because it is equal to 1000^5. It is based on the model of tera- (from Greek τέρας = 'monster', but looking like tetra- from the Greek for "four" with a letter missing, and so peta-, coming from penta-, omits the third letter, n.