I remember the first time I got an email from a publisher saying they’d like to turn my dissertation into a book. My ego suggested that this was obviously because someone figured out that my work was so awesome. Sadly, nope, my research’s awesome was not to explain the email. Rather, this was just a for-profit publisher that seeks to make money off of insecure (emotionally or labor market-ly) scholars. Generally speaking, if your work is solicited by email, assume that this may not be the best place to put your work.
How can you know? My first step is usually to google “[journal name] predatory vanity”. And see what pops up.
Predatory presses tend to be those that charge a high fee to authors to publish AND have no real peer review process.
Vanity presses are similar but they may do some minimal peer review but publish just about anything anyway.
What does it matter?
All publications are not made equal. Having a “bad” press publication is probably worse than having no publication, since it would signal naïveté and wouldn’t be considered a peer reviewed research paper for academic jobs or tenure/promotion decisions.