# Login

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Login
> Markdown URL: https://mediated.wiki/source/Login.md
> Source: https://en.wikipedia.org/wiki/Login
> Source revision: 1349859366
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Process by which an individual gains access to a computer system}}
{{redirect-distinguish|Logon|Logone (disambiguation){{!}}Logone}}
{{redirect|Logout|the film|Logout (film)}}
{{Redirect-several|Login}}
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{{Self-reference|To log in to Wikipedia, use Special:UserLogin. To log out from Wikipedia, use Special:UserLogout.}}
{{More citations needed |date=February 2024}}

[[File:Log in.tif|thumb|A screenshot of the [English Wikipedia](/source/English_Wikipedia) login screen in mobile mode]]

In [computer security](/source/computer_security), '''logging in''' (or '''logging on''', '''signing in''', or '''signing on''') is the process by which an individual gains [access](/source/Access_control) to a [computer system](/source/computer_system) or program by [identifying](/source/Proof_of_identity) and [authenticating](/source/Authentication) themselves.

Typically, [user](/source/User_(computing)) [credential](/source/credential)s consist of a [username](/source/User_(computing)) and a [password](/source/password).<ref>{{cite web|title=Detail and definition of ''login'' and ''logging in''|url=http://www.linfo.org/login_def.html|website=[The Linux Information Project](/source/Linux_Foundation)|access-date=1 January 2014|archive-date=25 December 2019|archive-url=https://web.archive.org/web/20191225010620/http://www.linfo.org/login_def.html|url-status=live}}</ref> These credentials themselves are sometimes referred to as ''a'' '''login'''.<ref>{{cite web|title=Definition of ''login''|url=http://www.oxforddictionaries.com/definition/english/login|url-status=dead|archive-url=https://archive.today/20140207023500/http://www.oxforddictionaries.com/definition/english/login|archive-date=7 February 2014|website=[Oxford Dictionaries](/source/Oxford_Dictionaries_(website))|access-date=8 February 2014}}.</ref> Modern secure systems often require a [second factor](/source/2FA), such as [email](/source/email) or [SMS](/source/SMS) confirmation for extra security. [Social login](/source/Social_login) allows a user to use an existing cell phone number or user [credentials](/source/Credential) from another email or [social networking service](/source/social_networking_service) to sign in or create an account on a new website.

When access is no longer needed, the user can '''log out''', '''log off''', '''sign out''' or '''sign off'''.

==Procedure==
[[File:Fingerprint scanner identification.jpg|thumb|left|[Finger print login](/source/Fingerprint), a banking security application]]
Logging in is usually used to enter a specific page, website, platform or application, which trespassers cannot see.

Once the user is logged in, the login token may be used to track what actions the user has taken while connected to the site.

Logging out may be performed when the [user](/source/User_(computing)) takes an action, such as entering an appropriate [command](/source/Command_(computing)) or clicking on an external link. It can also be done implicitly, such as by the user powering off their workstation, closing a [web browser](/source/web_browser) window, leaving a website, or not refreshing a website within a defined period.

A login page may have a return [URL](/source/URL_redirection) parameter, which specifies where to redirect back after logging in or out. For example, it is <code>returnto=</code> on this site.

In the case of websites that use [cookies](/source/HTTP_cookie) to track sessions, when the user logs out, session-only cookies from that site will usually be deleted from the user's computer. In addition, the server invalidates any associations with the session, thereby making any session handle in the user's cookie store useless.

This feature comes in handy if the user is using a [public computer](/source/public_computer) or a computer that is using a [public wireless connection](/source/Wi-Fi_hotspot). As a security precaution, one should not rely on implicit means of logging out of a system, especially not on a public computer; instead, one should explicitly log out and wait for confirmation that this request has taken place.

Logging out of a computer, when leaving it is a common security practice preventing unauthorized users from [tampering](/source/Tampering_with_evidence) with it. Some people choose to have a password-protected [screensaver](/source/screensaver) set to activate after some period of inactivity, thereby requiring the user to re-enter their login credentials to unlock the screensaver and gain access to the system.

'''Methods of Logging In'''

They include:

* Image recognition
* Fingerprints scanning
* [eye scan](/source/Iris_recognition)
* face scan
* passwords (oral or textual input)

==History and etymology==
[[File:IBM AIX 4 Login Prompt.jpeg|thumb|[IBM AIX](/source/IBM_AIX) Version 4 console login prompt]]
The terms "login" and "logon" became common with the [time sharing](/source/time_sharing) systems of the 1960s and [Bulletin Board System](/source/Bulletin_Board_System)s (BBS) in the 1970s.

Early [home computers](/source/home_computers) and [personal computer](/source/personal_computer)s did not generally require them until [Windows NT](/source/Windows_NT), [OS/2](/source/OS%2F2) and [Linux](/source/Linux) in the 1990s.

The term ''login'' comes from the verb ''(to) log in'' and by analogy with the verb ''to clock in''.

Computer systems keep a ''[log](/source/Logging_(computing))'' of users' access to the system. The term "log" comes from the [chip log](/source/chip_log) which was historically used to record distance traveled at sea and was recorded in a [ship's log](/source/ship's_log) or [logbook](/source/logbook).

To ''sign in'' connotes the same idea but is based on the analogy of manually signing a log book or [visitor's book](/source/guestbook).

While there is no agreed difference in meaning between the terms ''login'', ''logon'' and ''sign''-''in'', different technical communities tend to prefer one over another – Unix, Novell, Linux, and Apple typically use ''login'', and Apple's [style guide](/source/style_guide) says ''"Users log in to a file server (not log on to)...".''<ref>{{cite web|date=30 April 2013|title=Apple Style Guide|url=https://help.apple.com/asg/mac/2013/ASG_2013.pdf|url-status=dead|archive-url=https://web.archive.org/web/20150217214323/https://help.apple.com/asg/mac/2013/ASG_2013.pdf|archive-date=17 February 2015|website=[Apple](/source/Apple_Inc.)|access-date=17 May 2015|page=96 & 97}}</ref>

By contrast, Microsoft's style guides traditionally suggested the opposite and prescribed ''log on'' and ''logon''.

In the past, [Microsoft](/source/Microsoft) reserved ''sign-in'' to access the Internet,<ref name="ms">"Use log on or log on to... Do not use log in, login", 2004, ''Manual of Style for Technical Publications'', 3rd edition, p. 295, Microsoft.com.</ref> but from [Windows 8](/source/Windows_8) onward it has moved to the ''sign-in'' terminology for local authentication.<ref>{{cite web|title=Sign in to or out of Windows|url=http://windows.microsoft.com/en-us/windows-8/sign-in-out-of-windows|url-status=dead|archive-url=https://web.archive.org/web/20121028180739/http://windows.microsoft.com/en-us/windows-8/sign-in-out-of-windows|archive-date=28 October 2012|website=[Microsoft](/source/Microsoft)|access-date=28 October 2012}}</ref>

==See also==
{{Wiktionary|login}}
{{Wiktionary|log in}}
{{Commons category|Login}}

* [Computer security](/source/Computer_security)
* [Credential lag](/source/Credential_lag)
* [Login session](/source/Login_session)
* [Login spoofing](/source/Login_spoofing)
* [OpenID](/source/OpenID)
* [Password](/source/Password)
* [Password policy](/source/Password_policy)
* [Personal identification number](/source/Personal_identification_number)
* [/var/log/wtmp](/source/utmp)

==References==
{{reflist}}

{{Authority control}}

Category:Authentication methods
Category:User interfaces
Category:Computer access control

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Adapted from the Wikipedia article [Login](https://en.wikipedia.org/wiki/Login) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Login?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.