Document review in patent litigation is the structured process of examining documents and electronically stored information to identify material relevant to the claims, defenses, and issues in a patent dispute. It typically forms a major part of the discovery process and may involve emails, technical documents, source code, engineering records, product specifications, laboratory results, communications, presentations, and other business records. The objective is not simply to locate documents containing particular keywords, but to determine whether the information is relevant, responsive to discovery requests, privileged, confidential, or otherwise significant to the litigation.The review generally begins with collection and processing of potentially relevant data, followed by deduplication, filtering, technology-assisted review or other prioritization techniques, and human review. Reviewers classify documents according to agreed criteria, such as relevance, responsiveness, privilege, confidentiality, and issue or claim relevance. In patent litigation, additional technical categorization may be required to determine whether a document relates to a particular accused product, patent claim, prior-art reference, technical feature, or period of development.The results of document review help counsel build the factual record for infringement, invalidity, damages, claim construction, and other litigation issues. A well-structured review also creates a defensible record of how potentially responsive information was identified and handled, which becomes particularly important when the volume of electronically stored information is substantial.