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
Networking
  • unshielded twisted pair (UTP)

    Unshielded twisted pair (UTP) is a ubiquitous type of copper cabling used in telephone wiring and local area networks (LANs).

  • Multiprotocol Label Switching (MPLS)

    Multiprotocol Label Switching (MPLS) is a switching mechanism used in wide area networks (WANs).

  • computer network

    A computer network is a group of interconnected nodes or computing devices that exchange data and resources with each other.

Security
  • three-factor authentication (3FA)

    Three-factor authentication (3FA) is the use of identity-confirming credentials from three separate categories of authentication ...

  • cyber espionage

    Cyber espionage (cyberespionage) is a type of cyber attack that malicious hackers carry out against a business or government ...

  • role-based access control (RBAC)

    Role-based access control (RBAC) is a method of restricting network access based on the roles of individual users within an ...

CIO
  • knowledge-based systems (KBSes)

    Knowledge-based systems (KBSes) are computer programs that use a centralized repository of data known as a knowledge base to ...

  • Sarbanes-Oxley Act

    The Sarbanes-Oxley Act of 2002 is a federal law that established sweeping auditing and financial regulations for public companies.

  • project charter

    A project charter is a formal short document that states a project exists and provides project managers with written authority to...

HRSoftware
  • employee engagement

    Employee engagement is the emotional and professional connection an employee feels toward their organization, colleagues and work.

  • talent pool

    A talent pool is a database of job candidates who have the potential to meet an organization's immediate and long-term needs.

  • diversity, equity and inclusion (DEI)

    Diversity, equity and inclusion is a term used to describe policies and programs that promote the representation and ...

Customer Experience
  • sales development representative (SDR)

    A sales development representative (SDR) is an individual who focuses on prospecting, moving and qualifying leads through the ...

  • service level indicator

    A service level indicator (SLI) is a metric that indicates what measure of performance a customer is receiving at a given time.

  • customer data platform (CDP)

    A customer data platform (CDP) is a type of software application that provides a unified platform of customer information that ...

Close