3.1 Modeling Information in Softwar

	In software systems, information modeling is of the most importance.
	The attributes of real-world objects that we choose to capture in your software and the way that we choose to represent them largely determine the operations that your system can perform and the questions that it can answer.
	In a semantic system this is even more important, because by modeling concepts and objects with sufficient rigor, it is possible to reuse data from one application in another.
	Each type of information model presents its own set of advantages and disadvantages.
	Often a single software system will support several representations of its information precisely in order to exploit the strengths of each.
	Semantic Web technologies are based on an information model that is designed to facilitate easy data sharing and interoperability.
	Sharing Information: Syntax and Semantics

The problem of sharing data between systems can be broken into two important sub problems: the syntactic sharing problem and the semantic sharing problem. The syntactic aspect of the data-sharing problem involves gaining access to the shared data, while the semantic aspect involves incorporating that information into the data structures of the consuming system.

Serialized Objects

The simplest and most straightforward: binary object serialization. With binary object serialization, the producer generates objects that represent the data that is to be shared, and the data values in these objects are then directly serialized as ordered collections of bytes.

3.1 Modeling Information in Softwar

Relational Databases

Relational database can offer significant improvements over serialized objects for exchanging information, but this approach is not without its own shortcomings. Relational databases are usually distinct, reusable components that are not concerned with the main business logic of a software system.

Extensible Markup Language (XML)

XML is currently a very popular and effective way of exchanging information. XML languages conform to a well-defined syntax that is compatible with many widely available parsers. XML can provide an effective solution to the syntax problem for data sharing. In spite of the strict constraints on XML’s structure, the lack of reserved keywords or predetermined vocabulary of terms makes it flexible enough to be used for a wide variety of applications.

Metadata and Data in Information Sharing

Data and metadata are different. Data is values, individual atoms of information, and metadata describes the relationship between those atoms and other data. The combination of data and metadata greatly reduces the information sharing problem at the semantic level. Together data and metadata make information portable because the relationships among data values remain independent from their storage.