The document discusses knowledge management and various systems used for knowledge management. It describes enterprise-wide knowledge management systems that manage both structured and unstructured knowledge. These include structured knowledge systems for formal documents, semistructured knowledge systems for items like emails and memos, and knowledge network systems that provide directories of expertise. It also discusses knowledge work systems tailored for knowledge workers and intelligent techniques like expert systems, case-based reasoning, neural networks, and data mining that are used to capture and apply knowledge.