Predatory journal
A journal that charges publication fees while providing little or no genuine peer review or editorial service.
Predatory journals monetise the pressure to publish. The tells cluster: unsolicited flattering email, promises of review in days, a scope so broad it means nothing, an editorial board that has not agreed to serve, an impact factor from an invented index, and a fee disclosed only after acceptance.
They matter to you twice over. Publishing in one wastes work and can damage a record; citing one imports unreviewed claims into your argument. Check whether the journal is in DOAJ, Scopus, or Web of Science, whether the editors are real and know they are listed, and whether anything it has published looks like it was read before it was posted.