Your question ends on "from a legal standpoint", but it seems you really are asking "what does this mean from a photography standpoint?" In other words, "why do I care as a photographer and what should be my next step towards finding out [whatever]".
Even though there's an explicit disclaimer in the license, my understanding is random advice found on a site like this isn't – by default – assumed to be legal advice under many (most?) legal systems.
Personally, I would rather see multiple questions about different areas (e.g. US, EU, etc.) than trying to lump it all together. These questions should definitely be discouraged from proliferating into a series, and they are on the edge of not belonging. However, a general overview of the concepts (especially with links on where to go for more information) is objective, important, useful, and on-topic – from a photography standpoint.