Petabyte is a unit of computer memory or data storage capacity equal to 1,024 terabytes. It is commonly abbreviated PB.
After Terabyte comes a Petabyte then Exabyte then Zettabyte then Yottabyte. Large organisations use petabytes of storage to hold massive amounts of data. People at home probably don’t use petabytes, they would use gigabytes, megabytes and occasionally kilobytes.