In information technology, a terabyte, or TB, is equal to 1,024 gigabytes, or GBs. However, this is sometimes approximated to 1,000 gigabytes for digital storage, such as in hard-drive capacity. The use of units varies between device manufacturers, and the ambiguity is a source of confusion.
The SI unit for kilo, meaning 1,000, is sometimes used for the number of bytes in a kilobyte. This is a source of confusion, because power-of-two disk storage and memory sizes, such as 1,024, are commonly used within information technology. As a result, some manufacturers use tebibytes, or TiB, to unambiguously refer to 1,024 gibibytes, GiB, rather than risk confusion with multiples of 1,000 when using the more common TB and GB units.