Browse Definitions :
Definition

at sign (address sign or @)

What is an at sign?

On the Internet, @ (pronounced "at" or "at sign" or "address sign") is the symbol in an E-mail address that separates the name of the user from the user's Internet address, as in this hypothetical e-mail address example: [email protected]

In business, @ is a symbol meaning "at" or "each." For example, it means "each" in "4 apples @ $.35 = $1.40." Perhaps because it was one of the standard characters designed into typewriters (usually with the upper shift key pressed), the @ was chosen for inclusion as one of the special characters in the ASCII set of characters that became standard for computer keyboards, programs, and online message transmission.

History of the at sign

In July, 1972, as the specifications for the File Transfer Protocol (FTP) were being written, someone suggested including some e-mail programs written by Ray Tomlinson, an engineer at Bolt Beranek and Newman, chief contractor on ARPANET (Advanced Research Projects Agency Network), the precursor of the Internet. In their book, Where Wizards Stay Up Late, Katie Hafner and Matthew Lyon describe how the @ sign got there:

Tomlinson....became better known for a brilliant (he called it obvious) decision he made while writing [the e-mail] programs. He needed a way to separate, in the e-mail address, the name of the user from the machine the user was on. How should that be denoted? He wanted a character that would not, under any circumstances, be found in the user's name. He looked down at the keyboard he was using, a Model 33 Teletype, which almost everyone else on the Net used, too. In addition to the letters and numerals there were about a dozen punctuation marks. "I got there first, so I got to choose any punctuation I wanted," Tomlinson said. "I chose the @ sign." The character also had the advantage of meaning "at" the designated institution. He had no idea he was creating an icon for the wired world.

This was last updated in October 2021
SearchCompliance
  • ISO 31000 Risk Management

    The ISO 31000 Risk Management framework is an international standard that provides businesses with guidelines and principles for ...

  • pure risk

    Pure risk refers to risks that are beyond human control and result in a loss or no loss with no possibility of financial gain.

  • risk reporting

    Risk reporting is a method of identifying risks tied to or potentially impacting an organization's business processes.

SearchSecurity
  • Pretty Good Privacy (PGP)

    Pretty Good Privacy or PGP was a popular program used to encrypt and decrypt email over the internet, as well as authenticate ...

  • email security

    Email security is the process of ensuring the availability, integrity and authenticity of email communications by protecting ...

  • Blowfish

    Blowfish is a variable-length, symmetric, 64-bit block cipher.

SearchHealthIT
SearchDisasterRecovery
  • What is risk mitigation?

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • fault-tolerant

    Fault-tolerant technology is a capability of a computer system, electronic system or network to deliver uninterrupted service, ...

  • synchronous replication

    Synchronous replication is the process of copying data over a storage area network, local area network or wide area network so ...

SearchStorage
  • direct access

    In computer storage, direct access is the process of reading and writing data on a storage device by going directly to where the ...

  • kibi, mebi, gibi, tebi, pebi and exbi

    Kibi, mebi, gibi, tebi, pebi and exbi are binary prefix multipliers that, in 1998, were approved as a standard by the ...

  • holographic storage (holostorage)

    Holographic storage is computer storage that uses laser beams to store computer-generated data in three dimensions.

Close