This is only a summary of the license. The legal text contains the terms of the license.
This license was previously known as the Standard Noncommercial License.
You can use and share the material for noncommercial purposes, as long as you give credit.
In most cases, simply providing a link to the original is enough. (Specifically, the original has to include a link to this license, or you can include one yourself.)
This license takes its definition of “noncommercial” from the Creative Commons licenses. Creative Commons has a page about its meaning here. One thing in particular to note is that “noncommercial” describes the use, not the user: Both for-profit and non-profit entities can use the material for noncommercial purposes.