What is DTD (Document Type Description)

The current state of Web technology – the “first generation” or “syntactic” Web – gives rise to well-known, serious problems when trying to accomplish, in a non-trivial way, essential tasks like indexing, searching, extracting, maintaining, and generating information. These tasks would, in fact, require some sort of ‘deep understanding’ of the information dealt with: in a “syntactic” Web context, on the contrary, computers are only used as tools for posting and rendering information by brute force. Faced with this situation, Tim Berners- Lee first proposed a sort of “Semantic Web” where the access to information is based mainly on the processing of the semantic properties of this information: “… the Semantic Web is an extension of the current Web in which information is given well-defined meaning (emphasis added), better enabling computers and people to work in co-operation” (Berners-Lee et al., 2001: 35). The Semantic Web’s challenge consists of being able to access and retrieve information on the Web by “understanding” its proper semantic content (its meaning), and not simply by matching some keywords.