<result><section shorttitle="How does SGML work?"> | |
<title>How is SGML and would you recommend it to your grandmother?</title> | |
<intro> | |
<para>You can break a typical document into three layers: structure, | |
content, and style. SGML works by separating these three aspects and | |
deals mainly with the relationship between structure and content.</para></intro> | |
<topic topicid="top4"> | |
<title>Structure</title> | |
<para>At the heart of an SGML application is a file called the DTD, or | |
Document Type Definition. The DTD sets up the structure of a document, | |
much like a database schema describes the types of information it | |
handles.</para> | |
<para>A database schema also defines the relationships between the | |
various types of data. Similarly, a DTD specifies <emph>rules</emph> | |
to help ensure documents have a consistent, logical structure.</para></topic> | |
<topic topicid="top5"> | |
<title>Content</title> | |
<para>Content is the information itself. The method for identifying | |
the information and its meaning within this framework is called | |
<emph>tagging</emph>. Tagging must | |
conform to the rules established in the DTD (see <xref xrefid="top4"/>).</para> | |
<graphic graphname="tagexamp"/></topic> | |
<topic topicid="top6"> | |
<title>Style</title> | |
<para>SGML does not standardize style or other processing methods for | |
information stored in SGML.</para></topic></section></result> |