After the paper is accepted, an editor needs to put it together with the rest of the accepted papers and edit them to have a consistent style and format. At the end the proceedings of the conference are published.
Most of the conferences publish only a PDF version of the proceedings which is also used for print in some cases.
To make sure all papers have a consistent format the conference employs either a
Word styles library and expect authors to adhere to those. In other cases the
conference publishes a LaTeX .class
file to be used by all
authors and expect that the submitted PDF files were generated using that
configuration file.