Most OERs have a Creative Commons license. Many of the licenses allow users to edit and customize the materials. Most of the licenses require users to provide credit to the original creator. The main CC licenses are listed below. The Creative Commons website has more useful information about license specifics. The License Chooser tool is helpful for navigating the decisions for generating a license for your work.
All images courtesy of Creative Commons.
Attribution (BY) is the most open license. It allows the user to redistribute, to create derivatives, such as a translation, and even use the publication for commercial activities, provided that appropriate credit is given to the author (BY) and that the user indicates whether the publication has been changed.
Attribution (BY) - NonCommercial (NC) is a condition that makes the CC licenses more restrictive and thus less open.
Attribution (BY) - ShareAlike (SA) is also an open license. The letters SA (share alike) indicate that the adjusted work should be shared under the same reuse rights, so with the same CC license.
Attribution (BY) - NonCommercial (NC) - ShareAlike (SA)
Attribution (BY) - NoDerivatives (ND)
Attribution (BY) - NonCommercial (NC) - No Derivatives (ND) is not an open license since the work cannot be remixed and/or adapted.
"Difference between open license and copyright with all rights reserved" by Boyoungc is licensed under CC BY-SA 3.0.
Positioning OER in the CC licensing spectrum” by Cable Greene is licensed CC BY