Terabyte Definition

A terabyte, abbreviated as TB or T, is a unit of information that is equal to approximately one trillion bytes or exactly 2 to the 40th power (i.e., 1,099,511,627,776) bytes.

A byte (represented by the upper-case letter B), is a contiguous sequence of eight bits that is used as a unit of memory, storage and instructions execution in computers. A bit (represented by a lower case b) is the most basic unit of information in computing and communications, and every bit has a value of either zero or one.

A terabyte is also equal to 1024 gigabytes. A gigabyte is equal to approximately one billion bytes or 1024 megabytes.

A terabyte is roughly the equivalent of the contents of books made from 50,000 trees. The books in the U.S. Library of Congress contain a total of approximately 20 terabytes of text. A typical video store may contain about eight terabytes of video data.

The term terabyte is used most often used with regard to backup devices such as tape drives and tape libraries. The use of this term will become increasingly common as a result of both the information explosion and the ever-larger capacities of storage devices.

For example, personal computers containing a terabyte or more of storage space have recently become practical and relatively inexpensive through the use of multiple high-capacity hard disk drives.

Moreover, tape drives with a capacity of roughly 100TB are being developed by IBM and several Japanese companies. A key to this huge leap in capacity is the shrinkage of the size down to the half-micron level of the magnetic particles in the coating on the tape in which the individual bits of data are stored.

The prefix tera originates from the Greek word teras meaning monster. It also resembles the Greek prefix tetra meaning four, and a terabyte is approximately the fourth power of 1000 bytes.

Created September 1, 2005.
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