Documentation is the structured practice of creating, organizing, and maintaining written records that explain how systems, products, or processes work—spanning from technical API specifications to user guides. Strong documentation serves as both a knowledge repository and communication bridge between creators and users, reducing support overhead while enabling self-service discovery. Effective documentation isn't just about what you write—it's about information architecture, anticipating reader needs through audience analysis, and building findability through thoughtful structure and navigation that lets users locate answers quickly without frustration.