Portable Document Format (PDF) is a file format used to present documents in a manner independent of application software, hardware, and operating systems.

You can render any page as a PDF by adding the renderAs attribute to the <apex:page> component, and specifying “pdf” as the rendering service. For example:

<apex:page renderAs="pdf">

Visualforce pages rendered as PDFs will either display in the browser or download as a PDF file, depending on your browser settings.

Useful Documentation