XML

XML (Extensible Markup Language) is a markup language that is flexible (extensible) and definable such that it can be used for a variety of applications.  RSS technologies are built upon XML.  XML files are plain text files that have been "marked up" (had tags added to the content).  RSS is a specifically defined type of XML file, with its own rules.  An XML file that contains an RSS feed must be formed by abiding by an RSS specification.  Here is an example of an RSS feed contained in an XML file:

<?xml version="1.0" encoding="windows-1252"?>
<rss version="2.0">
<channel>
        <title>CIS 3720 - Dr. Garrett&apos;s Feed</title>
        <description>This is the feed for CIS 3720</description>
        <link>//ux1.eiu.edu/~cfnag/cis3720/3720.xml</link>
        <lastBuildDate>Tue, 23 Jan 2007 13:40:50 -0600</lastBuildDate>
        <pubDate>Tue, 23 Jan 2007 09:55:40 -0600</pubDate>
        <generator>FeedForAll v1.0 (1.0.1.0)</generator>
        <image>
                <url>http://ux1.eiu.edu/~nagarrett/cis3720/garrettn-3720.jpg</url>
                <title>Dr. Garrett&apos;s CIS 3720 Page</title>
                <link>http://eiu.ngarrett.org/3720.htm</link>
                <description>CIS 3720 at Eastern Illinois University</description>
                <width>117</width>
                <height>121</height>
        </image>
        <item>
                <title>Allen Lange&apos;s Feed</title>
                <description>Here is the link to Allen Lange&apos;s feed</description>
                <link>http://pen.eiu.edu/~adlange/Session/Session.xml</link>
                <author>Garrett</author>
                <category domain="">Feeds</category>
                <pubDate>Tue, 23 Jan 2007 09:55:40 -0600</pubDate>
        </item>
</channel>