The Situational Awareness and Preparedness for Public Health Incidences and Reasoning Engines (SAPPHIRE) is basically a semantics-based health information system which is accomplished of pursuing and assessing conditions and their existences that might affect public health domain. SAPPHIRE is based upon the development of Semantic Web technologies (a set of formats and programming languages) that find and analyze data on the WWW to permit the users online to realize and exploit organized information. The SAPPHIRE system gathers, organizes and imparts information on happenings and events that are important, to prepare and act on assisting public health-care professionals. Permits distinctly interpreted data, meeting the needs of miscellaneous industries, users and corrections rather than a general, universal design. The SAPPHIRE system was being developed by the Health Science Center using the RDF technologies. Integrates an extensive range of data from either the local health care providers, hospitals, environmental protection agencies or from the scientific literature. It allows health executives to measure the information through different domains like tracking the spread of influenza or the cure of HIV cases. In the greater Houston area, SAPPHIRE receives reports on emergency room cases at every 10 minutes, the reports of patients’ self-reported symptoms, updating of automated health records. Semantic Web technologies integrates these all information into a single plat former view of health conditions currently across the area. The primary key feature is supposed to be an ontology that is able to classify unexplained illnesses which presents flulike symptoms (fevers, coughs and sore throats) as potential influenza cases and then reports them to the Centers for Disease Control and Prevention automatically. Due to automatically generated reports, SAPPHIRE has relieved approx. nine nurses from doing such work manually, so that they are available for active nursing. It now conveys reports up to two to three days faster than before it conveyed. The smartness of Semantic Web technologies allows SAPPHIRE to operate efficiently in other situations as well. SAPPHIRE succeeded in recognizing gastrointestinal, respiratory and conjunctivitis outbreaks in disaster survivals. SAPPHIRE’s flexibility is a significant lesson about Semantic Web systems: once are configured for a broad problem. SAPPHIRE succeeds of only it can merge information from numerous areas, which can then be useful for different areas. By using a Semantic Web vocabulary, the FOAF (Friend of a Friend) system discovers mutual interests among friends and associates, even if they were not belonged to the similar social-networking sites like MySpace or Facebook. FOAF supporters are now developing networks that are semantic trust in order to find a way to fight e-mail spams.