The japanese call them BBSes or imageboards. The "chan" name was only made up by westerners because everyone was copying 4chan's name, which it copied from Futaba Channel's domain name "2chan", which in turn was copied from 2channel. The other Japanese image boards don't use any kind of "chan" in their name, and rarely ever refer to themselves as any kind of "channel". "Channel" tends to turn up mostly when copying 2channel.