LINE is a communication software that is predominantly used in Japan, Taiwan, Indonesia(maybe others? South Korea?). It is clunky, buggy, files expire fast, can't upload for a lot of extensions, only login-able on 1+1 devices (phone+computer). And people still use it, also there is no avoiding it if you want to get anything official done around these parts. I do see youngsters using Instagram and Threads, and a bit of Telegram sprinkled here and there but that's it. You want to get the job done, you use LINE. It's THE communication app.