Just writing a good research paper for a scientific journal is often enough to get published. Publishing one’s article often involves considerable monetary expenses as well. There are certain misconceptions about publishing that need to be clarified on the matter of author charges; (a) not all well-reputed peer-reviewed journals publish good quality articles for free and (b) any journal asking for an article processing charge is not necessarily a fraud or predatory journal.
Asking authors for certain charges for publication is a common practice that depends on the various business models followed by different journals, which in turn determines how they monetize the entire process. Depending on the business models, there are numerous forms of charges or levies that different journals impose on authors.
Well established traditional journals that have a substantive subscription base or a well-endowed trust to back their activities often do not charge fees from authors. But that too is not a set norm as many of them may charge some or nominal charges nonetheless. Some journals today do not charge money for the digital versions of the articles but request contribution to cover printing charges and distribution. Open access journals, which are often digital-only, may also charge fees to cover for peer-review and other administrative or operational expenses. There are different business models even for open access journals where some maybe subscription-based while others giving free access to anyone. Depending on the mode of access, the article processing charges may vary.
In most cases, good academic institutions are subscribers of good journals or have a membership or other such arrangements, such that any author from these institutions offering a research paper or review article for publication get institutional monetary support. This may be in the form of discount rates or even nominal expense coverage/grants for publication.
Some of the typical forms of charges associated with publishing in a scientific journal are:
Submission fee: many peer-reviewed journals levy a submission fee at the time of the review article submission. While authors may find this practice to be restrictive, some journals levy it only to keep spamming or substandard submissions at bay.
Membership fee: some journals seek to develop long-term relationships with authors and charge a membership fee. This covers charges for a specified number of articles over some specified time. Some also seek authors to do peer-review for other articles in exchange for getting their articles reviewed. The charges may depend on the type of engagement.
Publication fees: this is the most commonly understood charge, also known as author publishing charges or article processing charges (both read as APC), that covers the actual cost of publication.
A peer-reviewed article may charge all or a combination of these charges for a research paper. Thus, you may be charged a subscription fee during submission, and only have to pay a publication fee if your articles qualify for publication after peer review.