Preprints are the collection of accepted papers produced prior to a meeting for distribution at the meeting (note that not all Workshops produce preprints). Preprints are provided solely for the meeting participants, normally as part of the registration fee, and are not for sale. They do not carry an ISBN.
Proceedings are produced after the meeting and contain only papers presented at the meeting. Proceedings volumes carry an ISBN and are printed and published by Elsevier Ltd. Proceedings volumes are kept on sale by the publisher for at least five years.
Congress Proceedings are the hard bound volume of a selection of papers, plenary lectures, panel/round table discussion reports, etc., which are produced after the IFAC World Congress, available from and sold by the IFAC publisher. Congress Proceedings may also be provided in the form of CD-ROMs available from the IFAC publisher.