Petabyte is 1,000,000,000,000,000. I just learned it in class the other day. Exabyte is next in line...Wikipedia, what don't they have? That site has like the mother of all information. I love it. You guys should look up TRD and see what it says. On the very last line, it says: "Due to TRD USA often rebranding performance parts from other companies and selling them at a higher price, TRD obtained an alternate definition to its acronym: Totally Retarded Discount."