The full form of TiB is Tebi Byte

A tebibyte is a unit of data storage that equals 2 to the 40th power, or 1,099,511,627,776 bytes.

While a terabyte can be estimated as 10^12 or 1,000,000,000,000 bytes, a tebibyte is exactly 1,099,511,627,776 bytes. This is to avoid the ambiguity associated with the size of terabytes. A tebibyte is 1,024 gibibytes and precedes the pebibyte unit of measurement.

Abbreviation: TiB

1 Terabyte = 10121012 bytes = 1 000 000 000 000 bytes

For KB, MB, GB and TB you add 3 to the exponent (3, 6, 9, 12, …)

When talking about “Tebi” (as in TiB) you are, or should be, using a base-2:

1 Tebibyte = 240240 bytes = 1 099 511 627 776 bytes

For KiB, MiB, GiB and TiB you add 10 to the exponent (10, 20, 30, 40, …)

For a while the term KB, MB, GB and TB was used to refer to the equivalent KiB, MiB, GiB and TiB. The problem is that they are similar (2,4%) at the KB, but almost 10% in Tera vs Tebi and increasing exponentialy.