Terabyte Definition | The Interactive Glossary

The last year the Encyclopaedia Britannica was printed was 2010. That final edition consists of 32 volumes, weighs nearly 130 pounds, and contains approximately 50 million words and 300 million characters. It requires roughly one gigabyte (GB) of disk space to store the entire text of that final volume. Since one terabyte (TB) is equivalent to 1000 gigabytes (GB), you could store approximately 1000 copies of the 2010 edition of the Encyclopaedia Britannica on a single hard drive with one terabyte of storage space.

While that may seem like an immense amount of disk space, in today's media-driven digital world, computers equipped with hard drives exceeding one terabyte are common. To gain a sense of how much electronic data we are storing, some examples are in order:

• In 1993, the total Internet traffic for the entire year amounted to approximately 100 TB. However, as of June 2008, some estimates of Internet traffic clocked 160 TB every second. By 2008, the Internet traffic per second exceeded the total traffic in all of 1993.
• Approximately 500 hours of video is uploaded to YouTube every minute. While video file size vary based on many factors, it's a virtual certainty that more than 1 TB of video files are added to YouTube every minute.
• Wikipedia contains millions of pages which require combined storage of approximately 10 TB.
• The Hubble Space Telescope collected more than 100 TB of data over the first 25 years of operation.

As you can see, we're creating a lot of data, and a terabyte of disk space – once unthinkably large – is now common on typical personal computers.

Also See: Byte, Bit, Gigabyte

Frequently Asked Questions

Who introduced the first 1 TB hard drive?

The first hard drive offering 1 TB of storage was released by Hitachi in 2007. The drive cost $399 ($.40 per GB), and was offered to computer manufacturers, as an upgrade for technically-inclined PC owners, and for use as an external storage device. In 2015, the same drive can be had for less than $100 on Amazon, and competition in the storage industry has reduced the typical cost per GB to around $.05.

Are consumer hard drives still increasing in storage capacity?

Consumer hard drives have plateaued over the last couple of years. Most new computers today are equipped with a hard drive between 500 GB and 2 TB in size, and this has been true for a couple of years. The trend right now is to improve the performance of hard drives rather than to increase storage capacity. The reason for this is that consumer storage needs aren't growing as quickly as they once were.

While some computer users – most notably photographers, videographers, and audio creatives – still need massive hard drives, the popularity of streaming video services like Netflix, and music services like Pandora and Spotify, mean that computer users are no longer downloading large files – they are streaming them instead. So while storage in the hosting industry is skyrocketing to support cloud-based storage systems and media-rich web applications, personal storage needs are not growing as quickly today as they have in the past.