Office documents to PDF
Word, Excel, PowerPoint, and OpenDocument files become PDFs through LibreOffice on the worker. The layout is a new rendering of the document. Fonts that are not installed on the server are substituted, and macros are not kept. These tools appear only when LibreOffice is enabled for the site.
Text documents
A DOCX, an older DOC, an ODT, or an HTML page is laid out as a document and written to PDF. Scripts in the HTML are not run. Remote images may be missing if the worker cannot fetch them. Use this when you need a page someone can read without the original program, and check headings and page breaks on the PDF before you send it.
Sheets and slides
A workbook is printed to PDF. A very wide sheet may be scaled to fit, and Excel macros stay behind. Slides become pages in the order they appear in the deck. Animations and speaker notes are not a second file. If the deck is already a PDF and you only need it smaller, use the PDF tools instead of converting it again.