Loose-leaf books are also called loose-leaf notebooks and loose-leaf notebooks. From the word "loose-leaf book", we can know that the inner pages (inner cores) of loose-leaf books can be taken out or added at will. Specially designed loose-leaf books can also be called efficiency manuals, multifunctional manuals, loose-leaf notebooks and general notebooks ... Loose-leaf books are one of the most commonly used stationery in daily work and study, and consist of covers, loose-leaf folders or coils and paper. The biggest difference with ordinary notebooks is that loose-leaf notebooks are more flexible to use, and the paper can be disassembled, replaced and combined at will, which is convenient for sorting. Users can also DIY according to their own preferences. Loose-leaf books can be used to make notes, notes and drafts.