Open access is a set of principles and practices by which research results are distributed online, without access fees or other barriers, in principle under one of the Creative Commons licenses.
CC BY license
https://creativecommons.org/licenses/by/4.0/
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, as long as attribution is attributed to the creator. The license allows commercial use.
CC BY-NC license
https://creativecommons.org/licenses/by-nc/4.0/
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for non-commercial purposes only, and only as long as attribution is attributed to the creator.
CC BY-NC-ND License
https://creativecommons.org/licenses/by-nc-nd/4.0/
This license permits reusers to copy and distribute the material in any medium or format only in unadapted form, only for non-commercial purposes, and only as long as attribution is attributed to the creator.
CC BY-NC-SA License
https://creativecommons.org/licenses/by-nc-sa/4.0/
This license permits reusers to distribute, remix, adapt, and build upon the material in any medium or format only for non-commercial purposes, and only as long as attribution is attributed to the creator. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.
CC BY-ND License
https://creativecommons.org/licenses/by-nd/4.0/
This license allows reusers to copy and distribute the material in any medium or format only in unadapted form and only as long as attribution is attributed to the creator. The license allows commercial use.
CC BY-SA License
https://creativecommons.org/licenses/by-sa/4.0/
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, as long as attribution is attributed to the creator. The license allows commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.