This is the 4655th most frequent Japanese word.
掲示板
Bulletin board.
In this sentence, '掲示板' is used to refer to a physical bulletin board where notices and information are posted.
掲示板に重要なお知らせがあります。
There is an important notice on the bulletin board.
Here, '掲示板' refers to an online forum or electronic message board for discussions.
ネット掲示板で質問を投稿しました。
I posted a question on the online forum.
This usage of '掲示板' again refers to a physical bulletin board, specifically in a school environment for announcements.