use the <glossary> element

<dfn>Ciphers</dfn>.</dd>

<dt><a name="apacheextensiontool">APache eXtension Tool</a> <a

name="apxs">(apxs)</a></dt> <dd>A perl script that aids in compiling <a

href="#module">module</a> sources into Dynamic Shared Objects (<a

href="#dso">DSO</a>s) and helps install them in the Apache Web

name="apxs">(apxs)</a></dt> <dd>A perl script that aids in compiling <glossary

ref="module">module</glossary> sources into Dynamic Shared Objects (<glossary

ref="dso">DSO</glossary>s) and helps install them in the Apache Web

server.<br /> See: <a

href="programs/apxs.html">Manual Page: apxs</a></dd>

<dt><a name="certificate">Certificate</a></dt>

<dd>A data record used for authenticating network entities such

    as a server or a client. A certificate contains X.509 information pieces

    about its owner (called the subject) and the signing <a

    href="#certificationauthority">Certification Authority</a> (called the

    issuer), plus the owner's <a href="#publickey">public key</a> and the

    about its owner (called the subject) and the signing <glossary

    ref="certificationauthority">Certification Authority</glossary> (called

    the issuer), plus the owner's <glossary ref="publickey">public

    key</glossary> and the

    signature made by the CA. Network entities verify these signatures

    using CA certificates.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

<dt><a name="certificatsigningrequest">Certificate Signing Request</a>

<a name="csr">(CSR)</a></dt> <dd>An unsigned <a

href="#certificate">certificate</a> for submission to a <a

href="#certificationauthority">Certification Authority</a>, which signs it

with the <a href="#privatekey">Private Key</a> of their CA

<a name="csr">(CSR)</a></dt> <dd>An unsigned <glossary

  ref="certificate">certificate</glossary> for submission to a <glossary

  ref="certificationauthority">Certification Authority</glossary>, which signs it

with the <glossary ref="privatekey">Private Key</glossary> of their CA

<em>Certificate</em>. Once the CSR is signed, it becomes a real

certificate.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

data encryption. Examples are DES, IDEA, RC4, etc.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

<dt><a name="ciphertext">Ciphertext</a></dt> <dd>The result after <a

href="#plaintext">Plaintext</a> is passed through a <a

href="#cipher">Cipher</a>.<br /> See: <a href="ssl/">SSL/TLS

<dt><a name="ciphertext">Ciphertext</a></dt> <dd>The result after <glossary

ref="plaintext">Plaintext</glossary> is passed through a <glossary

ref="cipher">Cipher</glossary>.<br /> See: <a href="ssl/">SSL/TLS

Encryption</a></dd>

<dt><a name="commongatewayinterface">Common Gateway Interface</a> <a

<dt><a name="configurationdirective">Configuration Directive</a></dt>

<dd>See: <a href="#directive">Directive</a></dd>

<dd>See: <glossary ref="directive">Directive</glossary></dd>

<dt><a name="configurationfile">Configuration File</a></dt>

<dd>A text file containing <a href="#directive">Directives</a>

<dd>A text file containing <glossary ref="directive">Directives</glossary>

that control the configuration of Apache.<br />

See: <a href="configuring.html">Configuration Files</a></dd>

<dt><a name="connect">CONNECT</a></dt>

<dd>An HTTP <a href="#method">method</a> for proxying raw data channels

<dd>An HTTP <glossary ref="method">method</glossary> for proxying raw data

channels

over HTTP. It can be used to encapsulate other protocols, such as the SSL

protocol.</dd>

<dt><a name="context">Context</a></dt> <dd>An area in the <a

href="#configurationfile">configuration files</a> where certain types

of <a href="#directive">directives</a> are allowed.<br /> See: <a

<dt><a name="context">Context</a></dt> <dd>An area in the <glossary

ref="configurationfile">configuration files</glossary> where certain types

of <glossary ref="directive">directives</glossary> are allowed.<br /> See: <a

href="mod/directive-dict.html#Context">Terms

Used to Describe Apache Directives</a></dd>

<dt><a name="digitalsignature">Digital Signature</a></dt>

<dd>An encrypted text block that validates a certificate or other file. A

    <a href="#certificationauthority">Certification Authority</a> creates a

  <glossary ref="certificationauthority">Certification Authority</glossary>

  creates a

    signature by generating a hash of the <em>Public Key</em> embedded in a

    <em>Certificate</em>, then encrypting the hash with its own <em>Private

    Key</em>. Only the CA's public key can decrypt the signature, verifying

<dt><a name="directive">Directive</a></dt> <dd>A configuration command

that controls one or more aspects of Apache's behavior.  Directives

are placed in the <a href="#configurationfile">Configuration

File</a><br /> See: <a href="mod/directives.html">Directive

are placed in the <glossary ref="configurationfile">Configuration

File</glossary><br /> See: <a href="mod/directives.html">Directive

Index</a></dd>

<dt><a name="dynamicsharedobject">Dynamic Shared Object</a> <a

name="dso">(DSO)</a></dt> <dd><a href="#module">Modules</a> compiled

    name="dso">(DSO)</a></dt> <dd><glossary ref="module">Modules</glossary> compiled

separately from the Apache httpd binary that can be loaded on-demand.<br />

See: <a href="dso.html">Dynamic Shared Object Support</a></dd>

data sent by the client to the server, while output filters process

documents on the server before they are sent to the client.  For

example, the <code>INCLUDES</code> output filter processes documents

for <a href="#ssi">Server Side Includes</a>.<br /> See: <a

for <glossary ref="ssi">Server Side Includes</glossary>.<br /> See: <a

href="filter.html">Filters</a></dd>

<dt><a name="fully-qualifieddomain-name">Fully-Qualified

a file is called. Generally, files have implicit handlers, based on the file

type. Normally, all files are simply served by the server, but certain

file types are "handled" separately.  For example, the

<code>cgi-script</code> handler designates files to be processed as <a

href="#cgi">CGIs</a>.<br />

<code>cgi-script</code> handler designates files to be processed as <glossary

  ref="cgi">CGIs</glossary>.<br />

See: <a href="handler.html">Apache's Handler Use</a></dd>

<dt><a name="header">Header</a></dt>

<dd>The part of the <a href="#http">HTTP</a> request and response that

<dd>The part of the <glossary ref="http">HTTP</glossary> request and response that

is sent before the actual content, and that contains meta-information

describing the content.</dd>

<dt><a name=".htaccess">.htaccess</a></dt> <dd>A <a

href="#configurationfile">configuration file</a> that is placed inside

the web tree and applies configuration <a

href="#directive">directives</a> to the directory where it is placed

<dt><a name=".htaccess">.htaccess</a></dt> <dd>A <glossary

    ref="configurationfile">configuration file</glossary> that is placed inside

  the web tree and applies configuration <glossary

ref="directive">directives</glossary> to the directory where it is placed

and all sub-directories.  Despite its name, this file can hold almost

any type of directive, not just access-control directives.<br />

See: <a href="configuring.html">Configuration Files</a></dd>

<dt><a name="httpd.conf">httpd.conf</a></dt>

<dd>The main Apache <a href="#configurationfile">configuration file</a>.

<dd>The main Apache <glossary ref="configurationfile">configuration

    file</glossary>.

The default location is <code>/usr/local/apache2/conf/httpd.conf</code>,

but it may be moved using run-time or compile-time configuration.<br />

See: <a href="configuring.html">Configuration Files</a></dd>

<dt><a name="https">HTTPS</a></dt>

<dd>The HyperText Transfer Protocol (Secure), the standard encrypted

    communication mechanism on the World Wide Web. This is actually just HTTP

    over <a href="#ssl">SSL</a>.<br />

    over <glossary ref="ssl">SSL</glossary>.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

<dt><a name="method">Method</a></dt> <dd>In the context of <a

href="#http">HTTP</a>, an action to perform on a resource, specified

<dt><a name="method">Method</a></dt> <dd>In the context of <glossary

    ref="http">HTTP</glossary>, an action to perform on a resource, specified

on the request line by the client.  Some of the methods available in

HTTP are <code>GET</code>, <code>POST</code>, and <code>PUT</code>.</dd>

Extensions.  It consists of a major type and a minor type, separated

by a slash.  Some examples are <code>text/html</code>,

<code>image/gif</code>, and <code>application/octet-stream</code>.  In

HTTP, the MIME-type is transmitted in the <code>Content-Type</code> <a

href="#header">header</a>.<br /> See: <a

HTTP, the MIME-type is transmitted in the <code>Content-Type</code> <glossary

  ref="header">header</glossary>.<br /> See: <a

href="mod/mod_mime.html">mod_mime</a></dd>

<dt><a name="module">Module</a></dt> <dd>An independent part of a

you can choose to include or exclude.  Modules that are compiled into

the Apache httpd binary are called <em>static modules</em>, while

modules that are stored separately and can be optionally loaded at

run-time are called <em>dynamic modules</em> or <a

href="#dso">DSOs</a>.  Modules that are included by default are called

run-time are called <em>dynamic modules</em> or <glossary

ref="dso">DSOs</glossary>.  Modules that are included by default are called

<em>base modules</em>.  Many modules are available for Apache that are

not distributed as part of the Apache HTTP Server <a

href="#tarball">tarball</a>.  These are referred to as <em>third-party

not distributed as part of the Apache HTTP Server <glossary

ref="tarball">tarball</glossary>.  These are referred to as <em>third-party

modules</em>.<br />

See: <a href="mod/">Module Index</a></dd>

<dd>The unencrypted text.</dd>

<dt><a name="privatekey">Private Key</a></dt> <dd>The secret key in a

<a href="#publickeycryptography">Public Key Cryptography</a> system,

  <glossary ref="publickeycryptography">Public Key Cryptography</glossary>

  system,

used to decrypt incoming messages and sign outgoing ones.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

See: <a href="mod/mod_proxy.html">mod_proxy</a></dd>

<dt><a name="publickey">Public Key</a></dt> <dd>The publicly

available key in a <a href="#publickeycryptography">Public Key

Cryptography</a> system, used to encrypt messages bound for its owner

available key in a <glossary ref="publickeycryptography">Public Key

  Cryptography</glossary> system, used to encrypt messages bound for its owner

and to decrypt signatures made by its owner.<br />

See: <a href="ssl/">SSL/TLS Encryption</a></dd>

Apache uses Perl Compatible Regular Expressions provided by the

<a href="http://www.pcre.org/">PCRE</a> library.</dd>

<dt><a name="reverseproxy">Reverse Proxy</a></dt> <dd>A <a

href="#proxy">proxy</a> server that appears to the client as if it is

<dt><a name="reverseproxy">Reverse Proxy</a></dt> <dd>A <glossary

    ref="proxy">proxy</glossary> server that appears to the client as if it is

an <em>origin server</em>.  This is useful to hide the real origin

server from the client for security reasons, or to load balance.</dd>

name="url">(URL)</a></dt>

<dd>The name/address of a resource on the

Internet.  This is the common informal term for what is formally

called a <a href="#uniformresourceidentifier">Uniform Resource

Identifier</a>.  URLs are usually made up of a scheme, like

called a <glossary ref="uniformresourceidentifier">Uniform Resource

  Identifier</glossary>.  URLs are usually made up of a scheme, like

<code>http</code> or <code>https</code>, a hostname, and a path.  A

URL for this page is

<code>http://httpd.apache.org/docs-2.1/glossary.html</code>.</dd>

identifying an abstract or physical resource.  It is formally defined

by <a href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>.

URIs used on the world-wide web are commonly referred to

as <a href="#url">URLs</a>.</dd>

as <glossary ref="url">URLs</glossary>.</dd>

<dt><a name="virtualhosting">Virtual Hosting</a></dt>

<dd>Serving multiple websites using a single instance of Apache.