This cheat sheet aims to define key phrases and concepts used to describe open source. It further provides a brief explanation of the words' meanings along with a link to a website where you may get further details.
General Terms
Open Source
Open source is source code that is made freely available for possible modification and redistribution.
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Any work that others can copy of modify freely by attributing to the original creator but without needing to ask for permission. Examples include textbooks, films, and music.
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Structured data that is machine-readable and can be freely used, shared, redistributed and built on without restrictions. The data must be available as a whole and at no more than a reasonable reproduction cost.
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Software that is free of charge, while its freedom of use is restricted by the creator. It is covered by copyright law and is often provided to achieve marketing goals. Examples include Skype and Adobe Acrobat.
Learn moreDigital Public Goods (DPG)
Open source software, open data, open AI models, open standards and open content that adhere to privacy and other applicable laws and best practices, do no harm and help attain the Sustainable Development Goals.
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Open-Source Software (OSS)
Open-source software refers to software that is designed to be publicly accessible and that makes source code available for anyone to see, modify, improve, and distribute. It is often developed collaboratively by a community rather than a single author or company.
Learn moreFree and Open Source Software (FOSS)
Free and open-source software allows users to edit, modify, or reuse the software’s source code. “Free” indicates that the software does not have constraints on copyrights; it does not refer to the price.
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Closed-source software has source code that is hidden and can only be modified by the person, team, or organization who created it. Closed-source software cannot be legally altered or copied, and it may only be used as intended.
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A software license is a legal instrument governing how the software can be used and distributed. There are three types of open-source licenses: public domain, permissive license and copyleft software license.
Open-Source License
An open-source license is a type of license for computer software and other products that allows the source code, blueprint or design to be used, modified and/or shared under defined terms and conditions.
Learn morePublic-Domain Software
Public-domain software is unlicensed and outside the scope of copyright, trademark, or patent protection. It can be modified, distributed, or sold without any attribution by anyone.
Learn morePermissive License
A permissive software license grants rights to use, modify, and redistribute the software with minimal restrictions. It stipulates limited requirements, such as that the original authors must be credited. Permissive licenses allow derivative work to be relicensed and become proprietary.
Learn moreCopyleft Software License
Copyleft software license grants users the rights to use, modify and distribute the program’s code, as long as the derivative works uses the same open-source licence to remain freely available to future users. It is protective, because the creator of the software must own the copyright of the works, and it is reciprocal because it makes future work open-source.
Learn moreCreative Commons (CC) Licenses
A Creative Commons license is a type of public copyright license that allows the creator to retain copyright while allowing others to copy, distribute, and make use of the work and ensures licensors get the credit for the work. They are four license elements designed so that creators have options to provide restrictions on how they want their work to be used.
Attribution (BY) License
Attribution license lets others distribute, remix, adapt, and build upon your work, even commercially, as long as they credit you for the original creation. All of the Creative Commons licenses require this condition.
Learn moreShare Alike (SA) License
Share Alike license allows you to copy, redistribute, remix, transform, and build upon the material in any medium for any purpose, even commercially, under the condition that credit is given, changes are indicated, and the material is distributed under the same license.
Learn moreNon-Commercial (NC) License
NonCommercial license is a Creative Commons license which a copyright holder can apply to their media to give public permission for anyone to reuse that media only for noncommercial activities.
Learn moreNo Derivatives (ND) License
No Derivatives (ND) license allows people to copy and distribute a work but prohibit them from adapting, remixing, transforming, translating, or updating it, in any way that makes a derivative. In short, people are not allowed to create “derivative works” or adaptations.
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