What's fair use?
“In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include—
Creative commons (or CC) is a type of license that eschews some conventional protections of copyright, but may retain others. The license is defined by the creator at the time of publication. As the CC website puts it - they 'let you change your license from all rights reserved, to some rights reserved.'
In it's basic definition, Public Domain includes works created: