Information on the web is increasing in every single second and redundancy in information is growing rapidly. The Semantic Web is an extension of the current Web. The original idea of the Semantic Web was to bring machine-readable descriptions to the data and documents already on the Web, in order to improve search and data usage. The Web was, and in most cases it still is, a vast set of static and dynamically generated Web pages linked together. Today, the Semantic Web is not only about increasing the expressiveness of Web information to enable the automatic or semiautomatic processing of Web resources and Web pages. Academia and industry have realized that the Semantic Web can facilitate the integration and interoperability of intra- and inter-business processes and systems, as well as enable the creation of global infrastructures for sharing documents and data, make searching and reusing information easier. In this present paper a theoretical attempt has been made to discuss the real world need, applications, opportunities, and challenges of Semantic Web.