XPATH is an addressing mechanism that lets u specify a path 
to an element. for ex: <article><title>can be distinguished 
from <person><title>. that's why u can describe different 
kinds of transations for the different <title> elements.

It is an XML query language to select specific parts of an 
XML document.Using XPATH you can address or filter elements 
and text in a XML document.For instance a simple XPATH 
expression like "Invoice/Amount" states find "Amount" node 
which are children of "Invoice" node.

it is a transformation language which lets u transform XML 
into some other format.For ex: u might use XSLT to produce 
HTML,or a different XML structure. u could even use it to 
provide plain text or to put the information in some other 
document format.

it is a transformation language which lets u transform XML 
into some other format.For ex: u might use XSLT to produce 
HTML,JSP,ASP or a different XML structure. u could even use 
it to 
provide plain text or to put the information in some other 
document format.

Data transformation among the database,xml and our front 
end ,its may be HTML,JSP,ASP or some other formates.

XML and the Java Technology are complementary. Java 
technology provides the portable,maintainable code to 
process portable,reusable XML data. In addition,XML and 
Java technology have a no. of shared features that make 
them the ideal pair for web computing,including being 
industry standards,platform 
independence,extensible,reusable,web-centric and 
internationalized.

The DOM is a tree based mechanism that allows u to load or 
create an XML document,gather errors if any: access and 
manipulate the information and structures contained within 
the document and save the document back out to an XML file 
if necessary. Construcing the DOM requires reading the 
entire XML structure and holding the object tree in 
memory,so it is much more CPU and memory intensive.
    the SAX is an event-driven ,serial-access mechanism for 
accesing XML documents. SAX is the fastest and least memory 
intensive mechanism that is currently available for dealing 
with XML documents.

a module that reads in XML data from an input source and 
breaks it up into chunks so that ur program knows when it 
is working with a tag,an attribute ,or element data.

A DTD specifies the kinds of tags that can be included in 
ur XML document,and the valid arguments of those tags .. 
elements,entities and attributes.

--> All tags must be balanced
--> All attribute values must be  in quotes
--> Any EMPTY element tags must end with /> or make them 
non-empty by adding a end tag
--> there must not be any isolated mark up characters in ur 
text data
--> elements must nest inside each other properly
--> well-formed files with no dtd may use attributes on any 
element,but the attributes must all be of type cdata by 
default.

C and C++ are programming languages with which u specify 
calculations,actions and decisions to be carried out.
SGML and XML are markup languages with which u can design 
ways of describing information,usually for 
storage,transmission or processing by  a program.

XML promises to simplify and lower the cost of data 
interchange and publishing in a web environment.XML is  a 
text based syntax that is readable by both computer and 
humans.XML offers data portability and reusability across 
different platforms and devices. it is also flexible and 
extensible,allowing new tags to be added without breaking 
an existing document structure.Based on Unicode,XML 
provides global language support.

XML, the extensible markup Language, is a universal syntax 
for describing and structuring data independent from the 
application logic.
--> XML isa markup language much like HTML
--> XML was designed to describe data
--> XML tags are not predefined.you must define ur own tags
--> XML is self-describing

XML(Extensible Markup Langauge)is all about describing 
data.An XML tag is not something predefined but it is 
something you have to define according  to your needs.Below 
is a XML which describes invoice data.
<?XML version="1.0" encoding="ISO-8859-1"?>
<student>
<studentnumber>111</studentnumber>
<studentname>SaranKumarReddy.C</studentname>
<totalmarks>790</totalmarks>
<average>79</average>
</student>

For instance in the above example of student all tags are 
defined according to student needs.The XML document is self 
explanatory,any one can easily understand looking at the 
XML data what exactly it means.

In the above example <student></student> tag is the root 
element.Root element is the top most elements for a XML.

XML is case sensitive.
Eg: <student> tag is not same as <Student> tag.

85% of users rely on search engines to locate information on
the Web. By registering your site with various search
engines, you make it easier for visitors to find your site
and the information that you have to offer.

A few search engines, like AltaVista and Infoseek, are case
specific. When submitting to these engines you may want to
make upper and lowercase versions of your main keywords. For
other engines, lower case versions of your keywords are
recommended. 

You should determine what keywords you think your visitors
will use to find your site. Think about your site's focus
and intended audience. Consider asking your customers or
visitors what keywords THEY would think to use to find you. 

META tags are optional lines of HTML code in the HEAD
section of your document that can be used to describe your
page. META tags provide descriptive information about your
site to search engines, but in a form that isn't displayed
by the browser. 

The relevant attributes for search engines are the
DESCRIPTION and KEYWORDS attributes. Only 25% of web sites
include META tags, and not all search engines use them to
rank pages, but many do. 

Meta  means "Information about information"

for every webpage it is  must because the search engine can 
search the relative webpages based on metacontent of the 
document.
in meta tag they used to mention some importent  keywords
in the web page.

DHML used events, methods, properties to insulate dynamism
in HTML Pages.

Simple explanation :

If anyone use JavaScript in a HTML page, called DHTML.

DHTML: Dynamic HTML. An extension of HTML that enables, 
among other things, the inclusion of small animations and 
dynamic menus in Web pages. DHTML code makes use of style 
sheets and JavaScript.

DHTML: Dynamic HTML. An extension of HTML that enables,
among other things, the inclusion of small animations and
dynamic menus in Web pages. DHTML code makes use of style
sheets and JavaScript.

When you see an object, or word(s), on a webpage that
becomes highlighted, larger, a different color, or a streak
runs through it by moving your mouse cursor over it is the
result of adding a DHTML effect. This is done in the
language coding and when the file of the webpage was saved
it was saved as the .dhtml format instead of .htm or .html.

DHTML sites are dynamic in nature. DHTML uses client side
scripting to change variables in the presentation which
affects the look and function of an otherwise static page.
DHTML characteristics are the functions while a page is
viewed, rather than generating a unique page with each page
load (a dynamic website).

On the other hand, HTML is static. HTML sites relies solely
upon client-side technologies. This means the pages of the
site do not require any special processing from the server
side before they go to the browser. In other words, the
pages are always the same for all visitors - static. HTML
pages have no dynamic content, as in the examples above.

Pros and cons