The primary goal of this survey is to classify the different tasks to which database concepts have been applied, and to emphasize the technical innovations that are required to do so. We focus on three classes of tasks related to information management on the WWW: (1) Modeling and querying the web, (2) Information extraction and integration, and (3) Web site construction and restructuring. The survey showed that powerful abstractions developed in the database community may prove to be the key...