**peta**- [PE tuh] (Greek: derived from **penta**-, "five"; a decimal prefix used in the international metric system for measurements).

Used in the metric [decimal] system as one quadrillion [U.S.] or **thousand** billionfold [U.K.], 10^{15} [1 000 000 000 000 000] The metric symbol for **peta**- is **P**.

**petabyte**:

1. A unit of computer memory or data storage capacity equal to 1 024 terabytes.

2. One quadrillion bytes. A typewritten page is said to have about 2 000 bytes of data per side; therefore, a megabyte represents a 500 text page per side and a petabyte would be 500 billion pages.

**petaflops**:

This represents 1 000 (10^{15}) teraflops (floating point operations) per second.

**petagram**:

**petahertz**:

One quadrillion hertz (10^{15}).

**petameter**: