glossary.xml revision 76eb69077590129aefe07872728f1a9cc28b7304
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<!-- $Revision: 1.15 $ -->
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings Copyright 2002-2004 The Apache Software Foundation
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings Licensed under the Apache License, Version 2.0 (the "License");
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings you may not use this file except in compliance with the License.
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings You may obtain a copy of the License at
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings Unless required by applicable law or agreed to in writing, software
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings distributed under the License is distributed on an "AS IS" BASIS,
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings See the License for the specific language governing permissions and
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings limitations under the License.
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<p>This glossary defines some of the common terminology related to
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsApache in particular, and web serving in general. More information
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaon each concept is provided in the links.</p>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<section id="definitions"><title>Definitions</title>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="authentication">Authentication</a></dt> <dd>The positive
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsidentification of a network entity such as a server, a client, or a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="howto/auth.html">Authentication, Authorization, and Access
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="accesscontrol">Access Control</a></dt>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>The restriction of access to network realms. In an Apache context
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings usually the restriction of access to certain <em>URLs</em>.<br />
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunahref="howto/auth.html">Authentication, Authorization, and Access
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>An unambiguous formula or set of rules for solving a problem in
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsa finite number of steps. Algorithms for encryption are usually called
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="apacheextensiontool">APache eXtension Tool</a> <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsname="apxs">(apxs)</a></dt> <dd>A perl script that aids in compiling <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#module">module</a> sources into Dynamic Shared Objects (<a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#dso">DSO</a>s) and helps install them in the Apache Web
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="programs/apxs.html">Manual Page: apxs</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>A data record used for authenticating network entities such
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings as a server or a client. A certificate contains X.509 information pieces
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings about its owner (called the subject) and the signing <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings href="#certificationauthority">Certification Authority</a> (called the
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings issuer), plus the owner's <a href="#publickey">public key</a> and the
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings signature made by the CA. Network entities verify these signatures
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings using CA certificates.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="certificationauthority">Certification Authority</a> <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsname="ca">(CA)</a></dt> <dd>A trusted third party whose purpose is to
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingssign certificates for network entities it has authenticated using
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingssecure means. Other network entities can check the signature to verify
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsthat a CA has authenticated the bearer of a certificate.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="certificatsigningrequest">Certificate Signing Request</a>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<a name="csr">(CSR)</a></dt> <dd>An unsigned <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#certificate">certificate</a> for submission to a <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#certificationauthority">Certification Authority</a>, which signs it
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingswith the <a href="#privatekey">Private Key</a> of their CA
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<em>Certificate</em>. Once the CSR is signed, it becomes a real
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingscertificate.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="cipher">Cipher</a></dt> <dd>An algorithm or system for
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsdata encryption. Examples are DES, IDEA, RC4, etc.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="ciphertext">Ciphertext</a></dt> <dd>The result after <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#plaintext">Plaintext</a> is passed through a <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#cipher">Cipher</a>.<br /> See: <a href="ssl/">SSL/TLS
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="commongatewayinterface">Common Gateway Interface</a> <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsname="cgi">(CGI)</a></dt> <dd>A standard definition for an interface
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsbetween a web server and an external program that allows the external
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsprogram to service requests. The interface was originally defined by
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<a href="http://hoohoo.ncsa.uiuc.edu/cgi/overview.html">NCSA</a> but
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsthere is also an <a href="http://cgi-spec.golux.com/">RFC
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="howto/cgi.html">Dynamic Content with CGI</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="configurationdirective">Configuration Directive</a></dt>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>See: <a href="#directive">Directive</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="configurationfile">Configuration File</a></dt>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>A text file containing <a href="#directive">Directives</a>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsthat control the configuration of Apache.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="configuring.html">Configuration Files</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="connect">CONNECT</a></dt> <dd>An HTTP <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#method">method</a> for proxying raw data channels over HTTP. It
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingscan be used to encapsulate other protocols, such as the SSL
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsprotocol.</dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="context">Context</a></dt> <dd>An area in the <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#configurationfile">configuration files</a> where certain types
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsof <a href="#directive">directives</a> are allowed.<br /> See: <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="mod/directive-dict.html#Context">Terms
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="digitalsignature">Digital Signature</a></dt>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>An encrypted text block that validates a certificate or other file. A
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings <a href="#certificationauthority">Certification Authority</a> creates a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings signature by generating a hash of the <em>Public Key</em> embedded in a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings <em>Certificate</em>, then encrypting the hash with its own <em>Private
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings Key</em>. Only the CA's public key can decrypt the signature, verifying
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings that the CA has authenticated the network entity that owns the
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="directive">Directive</a></dt> <dd>A configuration command
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsthat controls one or more aspects of Apache's behavior. Directives
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsare placed in the <a href="#configurationfile">Configuration
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsFile</a><br /> See: <a href="mod/directives.html">Directive
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="dynamicsharedobject">Dynamic Shared Object</a> <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsname="dso">(DSO)</a></dt> <dd><a href="#module">Modules</a> compiled
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsseparately from the Apache httpd binary that can be loaded on-demand.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="dso.html">Dynamic Shared Object Support</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="environmentvariable">Environment Variable</a> <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>Named variables managed by the operating system shell
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsand used to store information and communicate between programs. Apache also
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingscontains internal variables that are referred to as environment variables,
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsbut are stored in internal Apache structures, rather than in the
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsshell environment.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="env.html">Environment Variables in Apache</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="export-crippled">Export-Crippled</a></dt>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>Diminished in cryptographic strength (and security) in order to comply
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings with the United States' Export Administration Regulations (EAR).
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings Export-crippled cryptographic software is limited to a small key size,
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings resulting in <em>Ciphertext</em> which usually can be decrypted by brute
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="ssl/">SSL/TLS Encryption</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="filter">Filter</a></dt> <dd>A process that is applied to
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsdata that is sent or received by the server. Input filters process
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsdata sent by the client to the server, while output filters process
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsdocuments on the server before they are sent to the client. For
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsexample, the <code>INCLUDES</code> output filter processes documents
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsfor <a href="#ssi">Server Side Includes</a>.<br /> See: <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="fully-qualifieddomain-name">Fully-Qualified
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsDomain-Name</a> <a name="fqdn">(FQDN)</a></dt> <dd>The unique name of
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsa network entity, consisting of a hostname and a domain name that can
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsresolve to an IP address. For example, <code>www</code> is a hostname,
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<code>www.example.com</code> is a fully-qualified domain name.</dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name="handler">Handler</a></dt> <dd>An internal Apache
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsrepresentation of the action to be performed when a file is
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingscalled. Generally, files have implicit handlers, based on the file
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingstype. Normally, all files are simply served by the server, but certain
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsfile types are "handled" separately. For example, the
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<code>cgi-script</code> handler designates files to be processed as <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="handler.html">Apache's Handler Use</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>The part of the <a href="#http">HTTP</a> request and response that
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsis sent before the actual content, and that contains meta-information
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsdescribing the content.</dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dt><a name=".htaccess">.htaccess</a></dt> <dd>A <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#configurationfile">configuration file</a> that is placed inside
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsthe web tree and applies configuration <a
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingshref="#directive">directives</a> to the directory where it is placed
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsand all sub-directories. Despite its name, this file can hold almost
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsany type of directive, not just access-control directives.<br />
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsSee: <a href="configuring.html">Configuration Files</a></dd>
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbings<dd>The main Apache <a href="#configurationfile">configuration file</a>.
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken StubbingsThe default location is <code>/usr/local/apache2/conf/httpd.conf</code>,
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingsbut it may be moved using run-time or compile-time configuration.<br />
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaSee: <a href="configuring.html">Configuration Files</a></dd>
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="hypertexttransferprotocol">HyperText Transfer
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaProtocol</a> <a name="http">(HTTP)</a></dt> <dd>The standard
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunatransmission protocol used on the World Wide Web. Apache implements
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaversion 1.1 of the protocol, referred to as HTTP/1.1 and defined by <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunahref="http://ietf.org/rfc/rfc2616.txt">RFC 2616</a>.</dd>
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dd>The HyperText Transfer Protocol (Secure), the standard encrypted
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna communication mechanism on the World Wide Web. This is actually just HTTP
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="method">Method</a></dt> <dd>In the context of <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunahref="#http">HTTP</a>, an action to perform on a resource, specified
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaon the request line by the client. Some of the methods available in
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaHTTP are <code>GET</code>, <code>POST</code>, and <code>PUT</code>.</dd>
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="messagedigest">Message Digest</a></dt>
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dd>A hash of a message, which can be used to verify that the contents of
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna the message have not been altered in transit.<br />
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="mime-type">MIME-type</a></dt> <dd>A way to describe the
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunakind of document being transmitted. Its name comes from that fact
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunathat its format is borrowed from the Multipurpose Internet Mail
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaExtensions. It consists of a major type and a minor type, separated
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaby a slash. Some examples are <code>text/html</code>,
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<code>image/gif</code>, and <code>application/octet-stream</code>. In
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaHTTP, the MIME-type is transmitted in the <code>Content-Type</code> <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="module">Module</a></dt> <dd>An independent part of a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaprogram. Much of Apache's functionality is contained in modules that
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunayou can choose to include or exclude. Modules that are compiled into
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunathe Apache httpd binary are called <em>static modules</em>, while
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunamodules that are stored separately and can be optionally loaded at
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunarun-time are called <em>dynamic modules</em> or <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunahref="#dso">DSOs</a>. Modules that are included by default are called
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<em>base modules</em>. Many modules are available for Apache that are
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunanot distributed as part of the Apache HTTP Server <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunahref="#tarball">tarball</a>. These are referred to as <em>third-party
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="modulemagicnumber">Module Magic Number</a> (<a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid LunaModule Magic Number is a constant defined in the Apache source code
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunathat is associated with binary compatibility of modules. It is changed
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunawhen internal Apache structures, function calls and other significant
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaparts of API change in such a way that binary compatibility cannot be
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaguaranteed any more. On MMN change, all third party modules have to be
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaat least recompiled, sometimes even slightly changed in order to work
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunawith the new version of Apache.
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna see <a href="http://www.openssl.org/">http://www.openssl.org/</a></dd>
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="passphrase">Pass Phrase</a></dt> <dd>The word or phrase
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunathat protects private key files. It prevents unauthorized users from
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaencrypting them. Usually it's just the secret encryption/decryption
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunakey used for <a name="cipher">Ciphers</a>.<br /> See: <a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="privatekey">Private Key</a></dt> <dd>The secret key in a
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<a href="#publickeycryptography">Public Key Cryptography</a> system,
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaused to decrypt incoming messages and sign outgoing ones.<br />
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Luna<dt><a name="proxy">Proxy</a></dt> <dd>An intermediate server that
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunasits between the client and the <em>origin server</em>. It accepts
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunarequests from clients, transmits those requests on to the origin
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaserver, and then returns the response from the origin server to the
6ee2adce4b7ba1c7cdee88dce16cc901d1a1e1ceDavid Lunaclient. If several clients request the same content, the proxy
449854c2a07b50ea64d9d6a8b03d18d4afeeee43Ken Stubbingscan deliver that content from its cache, rather than requesting it