Predatory publishing: Publishing that takes advantage of the Article Processing Charge model (where authors pay fees to offset costs) to take money upfront from authors and provide little to no peer review. These journals are often entirely deceptive, claiming to represent organizations they do not represent, have journal impact factors they do not have, and claim to be indexed in places they are not. This term does not refer to other types of poor scholarly journals, such as vanity journals or websites posing as academic journals to spread disinformation. The Article Processing Charge (APC) model for Open Access publishing is a legitimate and common model, currently being promoted in Europe by cOAlition S to make grant funded scholarship immediately Open Access. An example of a properly run APC journal is PLoS ONE, and their information on fees is here: https://journals.plos.org/plosone/s/publication-fees. Note that fees are not collected until after articles are refereed and accepted. More information on identifying predatory publishers at https://thinkchecksubmit.org/.
Predatory conferences: These conferences are similar to predatory publishers in that they take money upfront from attendees/speakers, do not represent organizations they claim to represent, and do not actually hold the promised conference. More information at https://thinkchecksubmit.org/think-check-attend/
Peer review: The review of a work by an expert on the subject. Authors may be asked to suggest reviewers when they submit their manuscript. There are a wide range of peer review models in current use, including single blind, double blind, triple blind, and open peer review. Single blind peer review, where the reviewers are not known to the author, is the most common type. Most models of peer review are prior to publication. Some newer models of peer review rely on posting pre-prints openly for wide scrutiny, and taking the openly solicited feedback into the peer review process. Others will do editorial review and then open the paper for post-peer review. Open peer review allows the review notes and each subsequent version of a work to be viewed, laying the entire process bare. This can help show the quality of feedback given by the reviewers and the guidance given by editors. Review done by an editor (editorial review) is usually considered part of peer review, but not a type of peer review.
Pre-print: A paper that has not undergone peer review. Typically this term is used in the depositing and self-archiving of pre-prints in institutional repositories.
Post-print: Also known as an author accepted manuscript (AAM). This is the post-peer reviewed version of a paper that has not yet been formatted by the journal into the publisher print. Usually these versions can also be self-archived.
Publisher print: The final version of a journal article put out by the publisher. Often this version cannot be self-archived or shared.