Guide
These labels all add visible information to PDF pages, but they serve different jobs. Knowing the difference helps you choose the right editing workflow.
A header or footer usually places short repeated text near the top or bottom margin of every page. This is useful for labels such as document status, confidentiality notes, review stage, or internal references.
Page numbers look similar, but they are a distinct feature because the content changes on each page. A good page-number tool usually needs formatting controls such as left, center, right, current page, and total pages.
A watermark is usually placed across the page content area instead of only near the edge. Common examples are Draft, Confidential, Sample, or Internal Use Only.
If you need a simple repeated note, use a header or footer workflow. If you need ordered numbering, use a page-number workflow. If you need a strong visible label over the content, use a watermark workflow.
A lightweight header-and-footer tool can stay simple by focusing on repeated text only. Page numbers and watermarks usually need different controls, so they often fit better as separate tools.
Open Add PDF Headers & Footers for simple repeated edge text, Browser-side PDF tools and privacy for the processing model, and How to merge multiple PDF files if you are preparing one final document from several sources.