terabyte

IPA/ˈterəbaɪt/
KK[tˌɛrəbˈaɪt]IPA/ˈterəbaɪt/

terabyte — noun

  • terabytesingular
  • terabytesplural

1. A measure of digital data size used in computing, where one terabyte equals 1,09

1.nounB2
Definition

A measure of digital data size used in computing, where one terabyte equals 1,099,511,627,776 bytes — the binary value that operating systems and software use to represent storage capacity and file sizes. This corresponds to 1024 gigabytes, with each level multiplied by 1024.

Example

Karim checked his computer and saw that his 1-terabyte drive reports 1024 gigabytes in the operating system's binary measurement.

operating system reports binary terabyte value

Raw video from Ignacio's documentary needed nearly two terabytes on the editing workstation — about 2000 gigabytes of 4K footage.

collocation: take up + [number] terabytes

Common collocations
  • half a terabyte
  • terabyte of data
  • terabyte of storage
  • terabyte drive
  • report in terabytes
  • show terabytes
Synonyms
  • tebibyte

    The official IEC term for 1,024 gibibytes (2^40 bytes). Used in technical documentation to avoid ambiguity with the decimal terabyte.

Grammar Patterns

a/the terabyte of [noun]

[number] terabytes of [noun]

Usage Note

This binary definition (based on multiples of 1024) is the value used by operating systems such as Windows, macOS, and Linux when displaying drive capacity or file sizes. Storage devices labelled with decimal terabytes will show a smaller number of binary terabytes when connected to a computer.

Common Mistakes

I bought a 2-terabyte hard drive, so my computer shows exactly 2 terabytes of free space.
I bought a 2-terabyte hard drive, but my computer shows only about 1.81 terabytes of space.
The decimal label (2,000,000,000,000 bytes) is about 10% smaller when converted to binary terabytes.
A terabyte is exactly 1,000 gigabytes.
A terabyte in computing is 1,024 gigabytes.
The binary system uses multiples of 1,024, not 1,000.

2. A measure of digital storage capacity, where one terabyte is set at exactly 1,00

2.nounB2
Definition

A measure of digital storage capacity, where one terabyte is set at exactly 1,000,000,000,000 bytes — the decimal value that hard drive, solid-state drive, and memory card manufacturers use on product packaging and in advertisements.

Example

Eli bought a 2-terabyte hard drive and expected 2,000 gigabytes of space.

product label uses decimal terabyte value

A memory card labelled '1 terabyte' gives about 931 gigabytes after formatting.

discrepancy between decimal label and actual usable space

Common collocations
  • labelled as X terabytes
  • terabyte hard drive
  • terabyte of cloud storage
  • terabyte plan
  • advertised as X terabytes
Synonyms
  • decimal terabyte

    An explicit term used in technical writing to distinguish this 10^12-byte unit from the binary terabyte (2^40 bytes).

Grammar Patterns

a/the terabyte [noun]

[number] terabyte [noun]

Usage Note

Hard drive and SSD manufacturers consistently use this decimal definition (1 TB = 1 trillion bytes) for their product labels. The difference between the decimal label and the binary reading shown by an operating system (sense 1) is roughly 9.95% — a 1 TB drive appears as about 931 GB in binary.

Common Mistakes

A 1-terabyte external drive gives you exactly 1,000 gigabytes of usable space.
A 1-terabyte external drive gives you about 931 gigabytes of usable space according to your computer.
The operating system counts in binary gigabytes (1,024 MB per GB), while the drive label uses decimal (1,000 MB per GB).

Synonym discussion

Sense: noun/1

Gigabyte, terabyte, and petabyte form a ladder of digital storage units, each about a thousand times larger than the previous. A gigabyte (GB) is familiar from phone storage and USB sticks, while a terabyte (TB) is typical for computer hard drives and backup disks. A petabyte (PB) is used for data-centre and cloud-scale capacity — one petabyte equals 1,024 terabytes. The tebibyte (TiB) is the IEC-standardised name for the binary 2^40-byte value (1,024 GiB), created specifically to end the confusion between binary and decimal prefixes. In practice, most consumers see 'TB' used for both definitions: hard-drive labels use decimal TB, while operating systems display binary TB. Knowing which definition applies helps avoid the common 'missing space' surprise when a new drive is connected to a computer.

gigabytepetabytetebibyte ↗

Common collocations

Nouns

Phrases

  • measured in terabytes
  • per terabyte
  • terabyte-scale

Etymology

GreekEnglish

The prefix 'tera-' comes from the Greek word 'teras' (τέρας), meaning 'monster' or 'prodigy', and was adopted as an SI prefix for 10^12 in 1960. 'Byte' was coined in 1956 by Dr. Werner Buchholz at IBM, originally spelled 'bite' (from the idea of a small unit of computer data), but altered to 'byte' to avoid confusion with 'bit'. The compound 'terabyte' entered common use in the early 2000s as hard-drive capacities grew past the gigabyte range.