ArXiv.org includes physics, mathematics, nonlinear science, computer science, quantitative biology and other disciplines. More than 500,000 papers were included in the preprint. Researchers need to typeset papers according to a certain format and upload them to the corresponding subject classification through the internet according to the subject category.
Managers in arXiv.org used to adopt a relaxed pre-trial system. They just look at the author's unit, paper format and general academic level. Generally uploaded papers can be published the next day. This is because arXiv.org acquiesced in the principle of literary responsibility. All published papers are numbered according to classification and date, which actually provides a written basis for the author's copyright.
The most important feature of arXiv.org is "open access", and others can access and download full-text data for free. Users can search and download directly from the browser.
Because of the above advantages of arXiv.org, arXiv.org has been widely welcomed by scientists for more than 20 years. Many scientists often "hang" their papers on the arXiv.org before formally submitting them to scientific journals. One is to have a written basis for copyright, and the other is to look at the reader's reaction.
The popular OA journals (open access) also have the characteristics of "open access". Most of them said that papers need to undergo strict peer review. However, because this is a "service" that charges authors, the academic level of OA journals varies greatly. For example, the world-famous Nature magazine has many OA sub-journals, and their peer review is strict, otherwise the reputation of Nature magazine will be affected. However, there are also many OA journals that are not strict in reviewing manuscripts. It seems that the main purpose is to charge authors.