The idea behind Creative Commons - a non-profit organization from the United States with departments around the world - is that some people don't want to exercise all the intellectual property rights that the law offers them. They offer their content or property with only 'some rights reserved' or even 'no rights reserved'. Because of these generous intentions, content - including video - offered under 'Creative Commons' can be freely adopted and used.
When you encounter (video) content on the internet that is presented under the Creative Commons principle, this content is free to copy and distribute on your own platform and therefore also on your own video platform. However, some content providers under the Creative Commons principle mention they would appreciate it if you mention the creator of the content.
More information on the principle of Creative Commons can be found on the official Creative Commons website.