Here are three things about various attributes that can be found in Creative Commons licences, which I find are not necessarily obvious, but good to know (details on the CC site).

First, when a CC licence has a NonCommercial (NC) designation, it means, roughly, that employing the work for a commercial use is not permitted. But it’s not quite that straightforward. The work’s creator wants other people to use the work (according to whatever permissions they’ve granted) but does not intend anyone acquiring the work through its Creative Commons licensed version, to profit from it.

There’s an interesting distinction though between use and user. You can’t make a blanket assumption about the use of the work based on the person or organization using it. Even a for-profit company for example, could use an NC designated work for a variety of things so long as they’re not selling it for profit (which would then qualify as commercial use).

The ShareAlike (SA) designation results in something like a viral impact. When someone licences a work with SA then other people that for example make something new with it, also have to release their new work with an SA designation in kind. This is beneficial in that those adopting it, potentially increase the availability of new works and ensure that work continues to be shared (nourishing the commons). This is akin to the requirements in Free software licences like the GPL, which have contributed to an extremely large Free and open source software ecosystem.

And finally, if the NoDerivatives (ND) aspect is present in a CC licence, it’s actually more permissive than it might sound. It does not prohibit making derivatives entirely. The Creative Commons pus a lot of emphasis on the commons, an effort in  large part to increase what we can all share access to. So in that sense, ND has more to do with the act of sharing a derivative than of making it. That’s to say, you can make a derivative work of an ND-licensed work but you don’t have the permission to distribute that derivative.