Public exchanges are when you trade with public people, meaning anyone can trade with you, if they want to. Public Exchanges are trading venues open to all interested parties (many sellers and many buyers) that use a common technology platform and that are usually run by third parties or industry consortia

Consortium

A consortium is an association of two or more individuals, companies, organizations or governments with the objective of participating in a common activity or pooling their resources for achieving a common goal....

. Public exchanges support community activities like distributing industry news, sponsoring online discussion

Online discussion

Online discussion is a relatively new form of communication, facilitated usually by computer networks. The first such communications were on mainframe-based systems such as the PLATO and CONFER systems in the early to mid 1970s. By the mid 1980's, dial-up bulletin board systems or "BBS's" run by...

 groups, blog

Blog

A blog is a type of website or part of a website supposed to be updated with new content from time to time. Blogs are usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in...

ging and providing research.

Source - Electronic Commerce 2008 - A Management Perspective (Efraim Turban). Page No.262 (Heading No. 6.1- B2B Electronic Exchanges - An Overview)