What Are Tags?
(From Flickr) You can give your photos and videos a "tag", which is like a keyword or category label. Tags help you find photos and videos which have something in common. You can assign up to 75 tags to each photo or video.

What is Creative Commons?
Creative Commons is a non-profit organization devoted to expanding the range of creative work available for others to build upon and share. Creative Commons has done the legal figuring to enable you to simply and easily express your preferences with respect to what people can do with your work. To adjust your Flickr license, visit your license preference page