Internet forum; Internet bulletin board
Refers to any web-based message board or discussion forum. Often abbreviated as 掲示板 (けいじばん) in context.
I posted a question on an Internet forum.
That Internet bulletin board is useful for exchanging information.
Loanword from English 'forum', often used for structured discussion sites, but インターネット掲示板 is more general.
Compound of インターネット (Internet) and 掲示板 (bulletin board).