The Jargon File (version 4.4.7, 29 Dec 2003):

bboard
 /bee'bord/, n.

    [contraction of ?bulletin board?]

    1. Any electronic bulletin board; esp. used of BBS systems running on
    personal micros, less frequently of a Usenet newsgroup (in fact, use of
    this term for a newsgroup generally marks one either as a newbie fresh in
    from the BBS world or as a real old-timer predating Usenet).

    2. At CMU and other colleges with similar facilities, refers to campus-wide
    electronic bulletin boards.

    3. The term physical bboard is sometimes used to refer to an old-fashioned,
    non-electronic cork-and-thumbtack memo board. At CMU, it refers to a
    particular one outside the CS Lounge.

    In either of senses 1 or 2, the term is usually prefixed by the name of the
    intended board (?the Moonlight Casino bboard? or ?market bboard?); however,
    if the context is clear, the better-read bboards may be referred to by name
    alone, as in (at CMU) ?Don't post for-sale ads on general?.


The Free On-line Dictionary of Computing (30 December 2018):

bulletin board system
bboard
BBS
bulletin board
CBBS
message board

    (BBS, bboard /bee'bord/, message
   board, forum; plural: BBSes) A computer and associated
   software which typically provides an electronic message
   database where people can log in and leave messages.  Messages
   are typically split into topic groups similar to the
   newsgroups on Usenet (which is like a distributed BBS).
   Any user may submit or read any message in these public areas.

   The term comes from physical pieces of board on which people
   can pin messages written on paper for general consumption - a
   "physical bulletin board".  Ward Christensen, the programmer
   and operator of the first BBS (on-line 1978-02-16) called it a
   CBBS for "computer bulletin board system".  Since the rise of
   the World-Wide Web, the term has become antiquated, though
   the concept is more popular than ever, with many websites
   featuring discussion areas where users can post messages for
   public consumption.

   Apart from public message areas, some BBSes provided archives
   of files, personal electronic mail and other services of
   interest to the system operator (sysop).

   Thousands of BBSes around the world were run from amateurs'
   homes on MS-DOS boxes with a single modem line each.
   Although BBSes were traditionally the domain of hobbyists,
   many connected directly to the Internet (accessed via
   telnet), others were operated by government, educational,
   and research institutions.

   Fans of Usenet or the big commercial time-sharing bboards
   such as CompuServe, CIX and GEnie tended to consider
   local BBSes the low-rent district of the hacker culture, but
   they helped connect hackers and users in the personal-micro
   and let them exchange code.

   Use of this term for a Usenet newsgroup generally marks one
   either as a newbie fresh in from the BBS world or as a real
   old-timer predating Usenet.

   (2005-09-20)