Terabyte (TB)

The prefix "tera" of terabyte is part of the SI or International System of Units, and means 10¹². Hard disk manufacturers label their products in SI, which may confuse some people in the IT field. The ISO, IEEE and the IEC all recommend using the unit tebibyte, which is more accurate for the measure of bytes signifying 1,024⁴ bytes.

Two interpretations can be made using the two standards:

• Using SI, one terabyte is equivalent to 1,000 gigabytes or 10¹² bytes
• Using traditional binary measurement, one terabyte is equivalent to 1,099,511,627,776 bytes, that’s 2^40, or 1024^4, bytes, also equivalent to 1 tebibyte (TiB)