Although there are lots of types of open licenses, open educational resources usually use a Creative Commons License. There are seven types of Creative Commons Licenses, including CC0, which means that no rights are reserved:
All Creative Commons Licenses (with the exception of CC0, no rights reserved) include some combination of the following four components. If you know the components, you can read a Creative Commons license!
Creative Commons licenses can be spelled out, abbreviated, or conveyed in symbols. For instance, "Creative Commons Attribution-NonCommercial-ShareAlike" means the same thing as "CC BY-NC-SA" or .