Novels and PDFs
An EPUB file and a PDF file open in a reader that is made for documents.
A comic archive and a source chapter are sets of images. The reading modes apply to them.
An EPUB file and a PDF file are documents. Suwatte opens them in a separate publication reader with controls that suit a document.
EPUB
An EPUB file has a flexible layout. The reader arranges the text to fit your screen. It uses the structure of the book: the table of contents, the chapter divisions and the internal links.
The text moves when you change a setting. A page number is therefore a result of your settings. It is not a property of the book.
EPUB Reader
Book Appearance
A PDF file has a fixed layout. The reader draws each page as the author made it. It gives you page controls and a zoom control, not text controls.
Where they come from
Both formats can come from a local file. They can also come from a server. Kavita and many OPDS catalogues hold EPUB files.
What stays the same
A novel and a PDF are normal library entries. Collections, flags, progress, history and backups treat them in the same way as a comic. They also go into your reading statistics.