There are Two Forms of access to research papers:

• Suscription model
• Open Acces model

I’m going to make a breef description for both of them:

Suscription model

In this case, the author does not have to pay to get his/her article published. Instead, the publisher charges the universities, institutions and readers, a suscription fee in order to access the research papers. However, since the scientific market follows an oligopolistic type of market, the suscriptions model has reached untenable costs levels. Therefore, the open access model has been developed

Open access model

In this models, the readers are not supposed to pay for the papers. However, somebody has to pay for the papers, therefore three open access models have been developed:

• Article Proccessing Charges (APC): In this case, the journals charge the author with some fees. The argument is that journal invest some money to edit and distribuite the paper. However, in top journal the fee can rech up to USD 2000.
• Not APC: in this case, the publisher, or the institution that edits the journal, funds all the activites and neither the author or reader must pay