Openness is an overarching concept or philosophy that is characterized by an emphasis on transparency and free, unrestricted access to knowledge and information, as well as collaborative or cooperative management and decision-making rather than a central authority. Openness can be said to be the opposite of secrecy.
Open government is the governing doctrine which holds that citizens have the right to access the documents and proceedings of the government to allow for effective public oversight.
Openness in government applies the idea of freedom of information to information held by authorities and holds that citizens should have the right to see the operations and activities of government at work. Since reliable information is requisite for accountability, freedom of access to information about the government supports government accountability and helps protect other necessary rights.
Open content and free content both refer to creative works that lack restrictions on how people can use, modify, and distribute them. The terms derive from open source software and free software, similar concepts that refer specifically to software.
Open education refers to institutional practices and programmatic initiatives that broaden access to the learning and training traditionally offered through formal education systems. By eliminating barriers to entry, open education aids freedom of information by increasing accessibility.
Open access refers to the practice of allowing peer-reviewed research articles to be available online free of charge and free of most copyright and licensing restrictions. Benefits of this approach include: accelerated discovery and progress as researchers are free to use and build on the findings of others, giving back to the public as much research is paid for with public funds, and greater impact for one's work due to open access articles being accessible to a bigger audience.