Sensor networks constitute a technological approach of increasing popularity when it comes to monitoring an area, offering context-aware solutions. This shift from Desktop computing to Ubiquitous computing entails numerous options and challenges in designing, implementing and shaping the behavior of systems that consume, integrate, fuse and exploit sensor data. Things tend to be more complicated when, in order to extract meaning from the collected information, the Semantic Web paradigm is adopted. In this talk, we discuss the information flow in systems that collect sensor data into semantically annotated repositories. Specifically, we analyze the journey that information makes, from its capture as electromagnetic pulses by the sensors, to its storage as a semantic web triples, along with its semantics in the system’s knowledge base. We introduce the main related concepts, we analyze the main components that such systems comprise, the choices that can be made, and the respective benefits, drawbacks, and effect to the overall system properties.