3. Define SGML
SGML stands for“standard generalized markup language”.
SGML,a system for organization & tagging elements of
document.
SGML developed & standardized by the international
organization for standard(ISO) in 1986.
SGML itself doesn’t specify any particular formatting;rather it
specifies the rules for tagging elements.
4. Define SGML cont….
SGML is not in itself a document language;but a description of
how to specify one.It is metadata.
SGML is a system for defining markup languages.
Author markup their document by representing structural,
presentational & semantic information along side content.
5. Define SGML cont….
HTML is one e.g.of a markup language,here is an e.g.of an
HTML document:-
<!doctype HTML public“-w3c//dtd html 4.01//EN”
http://www/w3.org/tr/html4/strict.dtd”>
<html>
<head>
<title>my 1st HTML document</title>
</head>
<body>
<p>hello world!
</body>
</html>
6. Define SGML cont….
above the HTML document is
divided into a head section & a body.The title of the document
appears in head & the content of the document appears in the body.
The body in this e.g.contains just one paragraph,marked up with
<p>.
o Every markup language defined in SGML is called an SGML
application.
o The language that this web browser uses,HTML is an e.g.of an
SGML based language.There is a document type definition for
HTML.
7. Advantages of SGML
1. Capable of dealing with any media type or linking protocol.
2. Extremely flexible
3. Separates content from appearance
4. Style sheets make content repurposing easy.
5. ISO standard- thus well supported with many tools available.
8. Disadvantages of SGML
1. Crating DTD’s requires exacting software engineering.
2. Linking tends to be complex.
3. Writing SGML software is extremely hard.
4. SGML tools trend to be expensive
5. SGML can be extremely complex and not widely used.
