The Copyright Clearance Center (CCC) provides a short video explaining the basics. Check it out for a better understanding of copyright issues regarding copying, sharing, and fair use.
The Copyright Clearance Center is an international licensing agency that licenses the rights to works with people in over 180 countries around the world. Such works include books, journal and newspaper content, websites, blogs, podcasts, music, artwork and more. To find out more about the CCC or about copyright issues, visit their website at Copyright.com.