A digital document is any document created, stored, or managed in electronic form, such as a PDF, email, scanned record, spreadsheet, or signed form in a document system. In cyber security, a digital document is not just a file: it also includes metadata, access permissions, version history, and sometimes signatures or seals that affect how it should be trusted and used.
This matters because attacks often target documents rather than systems. An attacker may alter content, steal confidential records, forge approvals, or use malicious document formats to deliver malware. Defenses focus on integrity and trust: cryptographic hashes, digital signatures, access control, audit logs, retention rules, and secure document management help prove whether a file changed and whether it is legitimate. In practice, a digital document can be intact but still untrusted if its origin, authorization, or legal status cannot be verified.