Every business keeps two kinds of truth: the numbers in the books, and the paper that proves them — the signed delivery note, the supplier's own invoice, the contract, the certificate, the bank's letter. The earlier chapters are the numbers. This chapter is the paper.
Documents are a module that is always on — like the accounts backbone, there is nothing to switch. Every company has them from its first day, because every company has files from its first day. The system gives each file one of three homes — attached to the record it belongs to, standing in the Document Library, or arriving through the capture inbox — and one filing system, the file plan, keeps all three in order without anyone playing librarian. Retention decides how long things are kept, and legal holds protect what must not be touched.
1.9 introduced attachments where they meet daily work. This chapter is the whole story behind them: where files live, how they are filed, how new paper arrives, what they cost you in storage, and how they are kept, archived and — only ever deliberately — removed.