Open content iscontent that is openly accessible, usable, editable, and distributable by anyone for any purpose, even commercially. Open content is licensed with anopen license that authorizes use of the content as described above.[1][2]
When someone creates something (like apicture orbook), they can open it for the use of others. This means that other people are allowed to copy it and change it if they want. Something that is open content may befree of charge, but it does not have to be.
TheSimple English Wikipedia is open content, and so are otherWikipedias. If a person changes open content or makes new open content, everyone can give it to anyone else, or even sell it.
The rules that say how people can use, change and pass around open content are called alicense. A license explains exactly what you are allowed to do with the content that falls under it. Licenses are often written in difficult language (legaljargon), but many licenses havesummaries that are much easier to understand.
The makers of open content get to choose what license to use for their work, and everyone else has to follow it. Only the maker, who owns thecopyright, can change it to another license. Most open content licenses say that when others change the work, they must also declare it to be open and under the same license. This is calledshare-alike and means that anything based on work will always be open content.
All the content in Wikipedia is open under the rules of theCreative Commons Attribution/Share-Alike License, a very well-known open content license. Another well-known open content license is theGNU Free Documentation License.
