Petabyte (PB) is the specification for extremely large storage capacities. In storage technology, this size occurs in tape drives and tape libraries. Peta (P) is the prefix of quadrillion (1,000,000,000,000,000), or 10exp15. In the dual system, a petabyte has a value of 2exp50. It is equivalent to 1,024 terabytes (TB) or over 1 million gigabytes
(GB). 1,024 petabytes form anexabyte
(EB). Although there are no special orders of magnitude for Big Data, size specifications in petabytes or in exabytes can be assigned to Big Data.