Thunderbird:Help Documentation:Glossary

This glossary is provided for your information only; it is not meant to be relied upon as a complete or authoritative description of the terms defined below or of the privacy and/or security ramifications of the technologies described.

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Glossary

authentication

The use of a password, certificate, personal identification number (PIN), or other information to validate an identity over a computer network.

cache

A collection of web page copies stored on your computer's hard disk or in its random-access memory (RAM). &brandShortName; accumulates these copies as you browse the Web. When you click a link or type a <a href="#Uniform_Resource_Locator">URL</a> to fetch a particular web page for which the cache already contains a copy, &brandShortName; compares the cached copy to the original. If there have been no changes, &brandShortName; uses the cached copy rather than refetching the original, saving processing and download time.

certificate

The digital equivalent of an ID card. A certificate specifies the name of an individual, company, or other entity and certifies that a public key, which is included in the certificate, belongs to that entity. When you digitally sign a message or other data, the digital signature for that message is created with the aid of the private key that corresponds to the public key in your certificate.

client

Software (such as an Internet browser) that sends requests to and receives information from a <a href="#server">server</a>, which is usually running on a different computer. A computer on which client software runs is also described as a client.

cookie

A small bit of information stored on your computer by some web sites. When you visit such a site, the site asks &brandShortName; to place one or more cookies on your hard disk. Later, when you return to the site, &brandShortName; sends the site the cookies that belong to it. Cookies help web sites keep track of information about you, such as the contents of your shopping cart. You can set your cookies options to control how cookies are used and how much information you are willing to let web sites store on them.

Cookie Manager

The part of &brandShortName; that you can use to control <a href="#cookie">cookies</a>.

cryptography

The art and practice of scrambling (encrypting) and unscrambling (decrypting) information. For example, cryptographic techniques are used to scramble and unscramble information flowing between commercial web sites and &brandShortName;.

decryption

The process of unscrambling data that has been encrypted. See also <a href="#encryption">encryption</a>.

digital ID

See <a href="#certificate">certificate</a>.

encryption

The process of scrambling information in a way that disguises its meaning. For example, encrypted connections between computers make it very difficult for third-parties to unscramble, or decrypt, information flowing over the connection. Encrypted information can be decrypted only by someone who possesses the appropriate key.

Extensible Markup Language (XML)

An open standard for describing data. Unlike HTML, XML allows the developer of a web page to define special tags. For more information, see the online W3C document <a href="http://www.w3.org/XML/">Extensible Markup Language (XML)</a>.

feed

An <a href="#XML">XML</a> web page that contains a list of links to other web pages. Special programs can read feeds to create a list of headlines from the links, automatically updating the list as it changes. News web sites use feeds to quickly publish the latest headlines, and personal online journals often use feeds to quickly notify visitors about new entries. See also <a href="#live_bookmark">live bookmark</a>.

File Transfer Protocol (FTP)

A standard that allows users to transfer files from one computer to another over a network. You can use &brandShortName; to fetch files using FTP.

FIPS PUBS 140-1

Federal Information Processing Standards Publications (FIPS PUBS) 140-1 is a US government standard for implementations of cryptographic modules — hardware or software that encrypts and decrypts data or performs other cryptographic operations (such as creating or verifying digital signatures). Many products sold to the US government must comply with one or more of the FIPS standards.

helper application

Any application that is used to open or view a file downloaded by &brandShortName;. A <a href="#plug-in">plug-in</a> is a special kind of helper application that installs itself into the Plugins directory of the main &brandShortName; installation directory and can typically be opened within &brandShortName; itself. Microsoft Word, Adobe Photoshop, and other external applications are considered helper applications but not plug-ins, because they don't install themselves into the browser directory but can be opened from the download dialog box.

Hypertext Markup Language (HTML)

The document format used for web pages. The HTML standard defines tags, or codes, used to define the text layout, fonts, style, images, and other elements that make up a web page.

Internet Message Access Protocol (IMAP)

A standard mail server protocol that allows you to store all your messages and any changes to them on the server rather than on your computer's hard disk. Using IMAP rather than POP saves disk space and allows you to access your entire mailbox, including sent mail, drafts, and custom folders, from any location. Using an IMAP server over a modem is generally faster than using a POP mail server, since you initially download message headers only. Not all ISPs support IMAP.

Internet

A worldwide network of millions of computers that communicate with each other using standard protocols such as <a href="#Transmission_Control_Protocol_Internet_Protocol">TCP/IP</a>. Originally developed for the US military in 1969, the Internet grew to include educational and research institutions and, in the late 1990s, millions of businesses, organizations, and individuals. Today the Internet is used for email, browsing the <a href="#World_Wide_Web">World Wide Web</a>, instant messaging, mailing lists and usegroups, and many other purposes.

Internet protocol address (IP address)

The address of a computer on a <a href="#Transmission_Control_Protocol_Internet_Protocol">TCP/IP</a> network. Every computer on the Internet has an IP address. <a href="#client">Clients</a> have either a permanent IP address or one that is dynamically assigned to them each time they connect with the network.

Java

A programming language developed by Sun Microsystems. A single Java program can run on many different kinds of computers, thus avoiding the need for programmers to create a separate version of each program for each kind of computer. After Java is installed, &brandShortName; can automatically download and run Java programs (also called applets).

JavaScript

A scripting language commonly used to construct web pages. Programmers use JavaScript to make web pages more interactive; JavaScript is often used to dynamically validate forms and select buttons. JavaScript can be used with Java, but it is technically a separate language. Java is not required for JavaScript to work correctly.

Lightweight Directory Access Protocol (LDAP)

A standard protocol for accessing directory services, such as corporate address books, across multiple platforms.

master password

A password used to protect saved passwords and other private data. &brandShortName; will prompt you for your master password when you wish to access this data. If you have multiple security devices, each security device will require a separate master password.

Password Manager

The part of &brandShortName; that can help you remember some or all of your names and passwords by storing them on your computer's hard disk and entering them for you automatically when you visit such sites.

PKCS #11

The public-key cryptography standard that governs security devices such as smart cards.

plug-in

A type of <a href="#helper_application">helper application</a> that adds new capabilities to &brandShortName;, such as the ability to play audio or video clips. Unlike other kinds of helper applications, a plug-in application installs itself into the Plugins directory within the main &brandShortName; installation directory and typically can be opened within &brandShortName; itself (internally). For example, an audio plug-in lets you listen to audio files on a web page or in an e-mail message. Macromedia Flash Player and Java are both examples of plug-in applications.

Post Office Protocol (POP)

A standard mail server protocol that requires you to download new messages to your local computer — although you can choose to leave copies on the server. With POP you can store all your messages (including sent mail, drafts, and custom folders) on one computer only. By contrast IMAP allows you to permanently store all your messages and any changes to them on the server, where you can access them from any computer. Most ISPs currently support POP.

private key

One of a pair of keys used in public-key cryptography. The private key is kept secret and is used to decrypt data that has been encrypted with the corresponding public key.

proxy

An intermediary or "go-between" program that acts as both a <a href="#server">server</a> and a <a href="#client">client</a> for the purpose of making requests on behalf of other clients.

secure site

A site that uses <a href="#encryption">encryption</a> in connections with &brandShortName; to prevent other malicious Internet users from viewing transmitted data. When you visit secure sites, &brandShortName; displays a lock icon in the <a href="#Status_Bar">Status Bar</a> and the <a href="#location_bar">Location Bar</a>. &brandShortName; also displays the site's domain name in the Status Bar (to prevent malicious sites from stealing your data) and turns the background of the Location Bar to yellow.

Some sites may consist of both secure and insecure data; the insecure data usually is non-private, although it isn't guaranteed to be so. For such sites &brandShortName; will display a lock icon with a slash through it in the Status Bar and Location Bar and will not display the site's domain name in the Status Bar so that you know that the current web page isn't completely secure.

Secure Sockets Layer (SSL)

A protocol that allows mutual authentication between a <a href="#client">client</a> and a <a href="#server">server</a> for the purpose of establishing an authenticated and encrypted connection. SSL runs above TCP/IP and below HTTP, LDAP, IMAP, NNTP, and other high-level network protocols. The new Internet Engineering Task Force (IETF) standard called Transport Layer Security (TLS) is based on SSL. See also <a href="#authentication">authentication</a>, <a href="#encryption">encryption</a>.

server

Software (such as software that serves up web pages) that receives requests from and sends information to a <a href="#client">client</a>, which is usually running on a different computer. A computer on which server software runs is also described as a server.

Status Bar

The toolbar that appears at the bottom of any &brandShortName; window. It shows status icons on the right.

TLS

See <a href="#Secure_Sockets_Layer">Secure Sockets Layer (SSL)</a>.

Transmission Control Protocol/Internet Protocol (TCP/IP)

A Unix protocol used to connect computers running a variety of operating systems. TCP/IP is an essential Internet protocol and has become a global standard.

web page

A single document on the World Wide Web that is specified by a unique address or URL. A web page may contain text, hyperlinks, and graphics.

web site

A group of related web pages linked by hyperlinks and managed by a single company, organization, or individual. A web site may include text, graphics, audio and video files, and links to other web sites.

World Wide Web

Also known as the Web. A portion of the Internet that is made up of web pages stored by web <a href="#server">servers</a> and displayed by <a href="#client">clients</a> called web browsers (such as &brandShortName;).