Predatory publishers are questionable, scholarly open-access publishers. Predatory publishers may have low standards for the quality of the articles they publish in their journals. They may ask for high fees...or even reasonable fees since they make money on the volume of articles rather than their scholarly reputation.
Authors should critically evaluate journals for their quality before deciding to publish. Read scope notes, journal descriptions, and journal reviews for criticism or red flags. Read other articles in the journal and evaluate them for quality. Examine the list of editors and reviewers for their qualifications and experience as editors. Well-meaning academics may get involved editing or reviewing for a predatory journal because they need experience for their tenure case or curriculum vita. Websites and e-mail communications may contain grammatical and spelling errors.
Predatory publishers have been known to publish a submitted article even when the open access fees were not paid so be careful.
Some publishers and distributors specialize in science publications or databases. Some are known for offering quality products. Scientists will become familiar with these names. It can help distinguish quality publications from those science publications offered by popular vendors.
However, always evaluate information critically. Even science publishers might publish an occasional dud. Even good researchers occasionally make mistakes.
University presses publish scholarly books and reports. Below are just a few examples.