All things on the Semantic Web are identified by URIs, e.g. wd:Q513 stands for Mount Everest and foaf:knows denotes the "knows" relationship between two people. The structured data about these entities is serialized and made available using multiple methods such as HTML-embedded JSON-LD, static Turtle files, and SPARQL endpoints.
Taken together, everyone's structured datasets form the global linked data cloud in which the URIs act as reusable identifiers—references to concepts, relationships, and real-world things. Dereferencing these URIs and extracting the data about the underlying entities is not always easy without knowing exactly where to look and how to use the linked data formats, protocols, and query languages. This is why I've created this Semantic Web Browser—an online tool for looking up "things" by their URIs that returns the authoritative information about the entities from around the linked data web.