Originally Posted by polish_aristocrat

"chat board" = people post whatever they feel at the moment, without putting much thought to it, or caring about spelling or grammar. Just like in a chatroom, what gets posted now, will be soon forgotten. Users enter the chat board to have fun or kill time.

"message board" = people trying to make their posts meaningful, discussing with other posters in at least slightly professional way, thinking carefully before publishing their post. People search the archives to find the answer to their questions, rather than spontaneously starting a new thread with their question. Posting garbage is not encouraged. Users spend their time on the message baord looking for answers to their questions and interesting discussions.

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