The yottabyte is a unit of information (or computer storage) equal to one septillion bytes (which is one long scale quadrillion or 1024) or equal to one quadrillion gigabytes.
Derived from the SI prefix yotta- as of 2011, no storage system has achieved one zettabyte of information. The combined space of all computer hard drives in the world does not amount to even one yottabyte, but was estimated at approximately 160 exabytes in 2006. As of 2009, the entire Internet was estimated to contain close to 500 exabytes.
The term "yobibyte" (YiB), using a binary prefix, is used for the corresponding power of 1024.