Open source license is a kind of legal license. Through it, the copyright owner explicitly allows users to use, modify and share the copyrighted software free of charge.

The copyright law prohibits sharing by default, that is, software without a license is equivalent to retaining copyright. Although it is open source, users can only look at the source code and can't use it. Once used, it will infringe copyright. Therefore, if the software is open source, the open source license must be explicitly granted to users.

Projects released on the open source platform need to choose the open source agreement, which can protect your rights and interests with certain rules. Different agreements have different terms.

Public Domain

Rights / interests are not owned by individuals or groups. These intellectual inventions belong to public cultural heritage.

TAPR Open Hardware License

This is the TAPR Open Hardware License, and like the GNU General Public License, the OHL is designed to guarantee your freedom to share and create. It prohibits anyone accepting the right under the OHL to deny the same rights to any other licensee to reproduce, modify and distribute the Documentation, and to make, use and distribute products based on the Documentation. It again differs from GPL, OHL is not primarily a copyright license.

CERN Open Hardware License

The documentation states:https://www.ohwr.org/projects/cernohl/wiki

The CERN–OHL is to hardware what the free and open-source licences are to software. It defines the conditions under which a licensee will be able to use or modify the licensed material. It shares the same principles as free software or open-source software: anyone should be able to see the source – the design documentation in the case of hardware – study it, modify it and share it.

GPL 3.0

The documentation states: https://opensource.org/licenses/GPL-3.0

LGPL：

The documentation states:https://opensource.org/licenses/lgpl-license

BSD：

The documentation states:https://opensource.org/licenses/BSD-2-Clause

MIT：

The documentation states:https://opensource.org/licenses/MIT

CC-BY 3.0：

The documentation states:https://creativecommons.org/licenses/by/3.0/

CC-BY-SA 3.0：

The documentation states:https://creativecommons.org/licenses/by-sa/3.0/

CC-BY-NC-SA 3.0：

The documentation states:https://creativecommons.org/licenses/by-nc-sa/3.0/

CC-BY-NC 3.0：

The documentation states:https://creativecommons.org/licenses/by-nc/3.0/