14. A system comprising: one or more processors; memory, in communication with the one or more processors; a module, defined in the memory, executable by the one or more processors, and configured to: obtain web documents based at least in part on a search term; extract a plurality of entities and entity relationships from the web documents, each of the plurality of entities related to, but distinct from, the search term; cause display of representations indicating each of the plurality of entities; cause display of edges to define pairs of the displayed representations, the edges indicated by the entity relationships; cause display of a representation of the search term and edges from the representation of the search term to each of the representations of the plurality of entities; receive user input indicating an edge between representations of two particular entities; and cause display of a description of a relationship between the two particular entities in response to the received user input.
14. A system comprising: one or more processors; memory, in communication with the one or more processors; a module, defined in the memory, executable by the one or more processors, and configured to: obtain web documents based at least in part on a search term; extract a plurality of entities and entity relationships from the web documents, each of the plurality of entities related to, but distinct from, the search term; cause display of representations indicating each of the plurality of entities; cause display of edges to define pairs of the displayed representations, the edges indicated by the entity relationships; cause display of a representation of the search term and edges from the representation of the search term to each of the representations of the plurality of entities; receive user input indicating an edge between representations of two particular entities; and cause display of a description of a relationship between the two particular entities in response to the received user input. 15. The system as recited in claim 14 , wherein the processor causes display of representations indicating each of the plurality of entities by: causing display of representations of entities connected by edges to more entities in a size larger than representations of entities connected by edges to fewer entities; and causing display of the representation of the search term in a size larger than representations indicating each of the plurality of entities.