Summary The OWL is the part of W3C stack for Semantic Web, its model is inferred from RDF model but having more flexibilty, so that any sort of relationship among the elements can be presented. One can design more complex relationships using OWL and the search would also be much easy as the contents are in their best form. So this is the only solution for searching the contents much faster as the contents are managed and secondly more readable to machine as well.

The web is considered as really really a huge library in which we can search and edit the contents. Now what about the searching methodologies for the huge contents to do so you must have organized contents to make the search fast and efficient. Already there are different methodologies and techniques are used for searching e.g. RDF and XML etc. but no one has fulfilled the entire requirement. OWL is basically designed for the applications in which content processing (content authoring) is important rather than just presenting the contents to humans. It would make the web search much intelligent and readable to machine as well.

It seems that future of the web languages would be Web Semantic and OWL is one of its activity. Here the question rises that what's the specialty of OWL, which is not provided in XML and XML Schema, the history intended as follows;

1. XML provides a syntax for structured documents, but doesn't define semantic constraints on the meaning of the documents.

2. XML Schema is a language for restricting the structure of XML documents.

3. RDF is a datamodel for objects (resources) and relations between them, provides a simple semantics for this datamodel, and these datamodels can be represented in an XML syntax.

4. RDF Schema is a vocabulary for describing properties and classes of RDF resources, with a semantics for generalization-hierarchies of such properties and classes.

5. OWL is nothing but enhanced RDF and it has more vocabulary for describing properties and classes: among others, relations between classes (e.g. disjointness), cardinality (e.g. exactly one), equality, richer typing of properties, characteristics of properties (e.g. symmetry), and enumerated classes.

6. An ontology is a knowledge representation of data rather than message format only i.e. in XML Schema. For example if your purchase order for any product is fulfilled, which can be presented in XML Schema as well but what about the context external to this transactions consensus i.e. the product has white color so it can't be sold.

It was the first attempt, which was made in defining relationships in XML documents. The basic model of RDF (Resource description framework) comprises of three following components;

Consider as a simple example the sentence:
Ijaz Ahmed is the administrator of the resource <http://www.emalangs.com>.

This sentence has the following parts:

 

Subject (Resource)	http://www.emalangs.com <http://www.binariez.com/>
Predicate (Property)	Administrator
Object (literal)	Ijaz Ahmed

The complete XML document presenting this information would look like;
<?xml version=1.0?>
<rdf:RDF xmlns:rdf=<http://www.w3.org/1999/02/22-rdf-syntax-ns>
xmlns:s=http://description.org/schema/>
<rdf:Description about=http://www.emalangs.com>
<s:Administrator>Ijaz Ahmed</s: Administrator >
</rdf:Description>
</rdf:RDF>

It also has three components i.e. Bags, Sequence and Alternative.

Using bags

<rdf:RDF>
<rdf:Description about=<http://www.emalangs.com>>
<s:Administrators>
<rdf:Bag>
<rdf:li resource=Network Administrator/>
<rdf:li resource=System Administrator/>
<rdf:li resource=Database Administrator/>
</rdf:Bag>
</s:Administrators>
</rdf:Description>
</rdf:RDF>

Using Alternative

<rdf:RDF>
<rdf:Description about=<http://www.emalangs.com>>
<s:Administrators>
<rdf:Alt>
<rdf:li resource=Network Administrator/>
<rdf:li resource=System Administrator/>
<rdf:li resource=Database Administrator/>
</rdf:Alt>
</s:Administrators >
</rdf:Description>
</rdf:RDF>

Using Sequence

<rdf:RDF>
<rdf:Description about=<http://www.emalangs.com>>
<s:Administrators>
<Seq ID=AdminByRole>
<rdf:li resource=Network Administrator/>
<rdf:li resource=System Administrator/>
<rdf:li resource=Database Administrator/>
</Seq>
</s:Administrators >
</rdf:Description>
</rdf:RDF>

From the above mentioned information you can at least you can conclude that the
three administrators have distinct roles/types, such a solution can't be explained
using RDF, XML or XML Schema.
OWL also has many flexibility in its model to present different sort of relationships
among the elements. For detail visit the URL;
<http://www.w3.org/TR/2003/WD-owl-guide-20030331/>

and for RDF parser and its detail visit;
<http://www.redland.opensource.ac.uk/demo>

The OWL is the part of W3C stack for Semantic Web, its model is inferred from
RDF model but having more flexibilty, so that any sort of relationship among the elements
can be presented the detail of which can be read at http://www.w3.org/TR/owl-ref/ - appA <http://www.w3.org/TR/owl-ref/>.
One can design more complex relationships using OWL and the search would also be much easy as the contents are in their best form. So this is the only solution for searching the contents much faster as the contents are managed and secondly more readable to machine as well.