bulletin board

noun
1.
a board for the posting of bulletins, notices, announcements, etc.
2.
Computers. BBS.
Origin
1825-35, Americanism
British Dictionary definitions for bulletin boards

bulletin board

noun
1.
(US & Canadian) a board on which notices, advertisements, bulletins, etc, are displayed Also called (in Britain and certain other countries) notice board
2.
(computing) a facility on a computer network allowing any user to leave messages that can be read by any other user, and to download software and information to the user's own computer
Contemporary definitions for bulletin boards
noun

See message board

bulletin boards in Science
bulletin board
  (bl'ĭ-tn)   
An electronic communication system that allows users to send or read electronic messages, files, and other data that are of general interest and addressed to no particular person. Bulletin boards were widely used before the Internet became popular, and many of their functions are now served by websites and newsgroups for specific topics or groups.
Idioms and Phrases with bulletin boards

bulletin board

Also, electronic bulletin board. A computer service that provides facilities for people to leave messages by phone or telecomputing. For example, The National Writers Union has a bulletin board through which members communicate via their modems. Both the device and the term, alluding to the older board for posting notices, date from the late 1970s.