Main Page | See live article | Alphabetical index For the bread, see: pita. Peta (symbol: P) is a prefix in the SI system of units denoting 1015, or 1 000 000 000 000 000. In computer science peta can mean 1 125 899 906 842 624 (10245 or 250), instead of 1 000 000 000 000 000, especially when used to prefix the byte, giving a petabyte. PETA is an organization: People for the Ethical Treatment of Animals This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.