A measurement of digital information storage or transmission, and a multiple of the unit "byte" using the International System of Units prefix.
Petabytes are 2^50, which is equal to 1,125,899,906,842,624 bytes when in relation to computer memory like RAM.
The PB are also 10^15, or 1,000,000,000,000,000 bytes when in relation to storage solutions like flash drives or hard drives.
PB are one of the larger measures of byte multiples and is hardly seen outside of large server farms run by large companies.
Very similar to Pebibytes, which use a more exact prefix established by the International Electrotechnical Commission.