Creative Commons is a nonprofit organization that enables the sharing and use of creativity and knowledge through free legal tools.
Creative Commons (CC) has written copyright licences which provide a simple, standardized way to give the public permission to share and use your creative work — on conditions of your choice.
There are six different CC licences, all of which require attribution of the author (denoted by BY in all licences' names). It is important you check which licence has been specified. This page explains the different licences.
Applying a CC licence to your works
If you want to make your works available with a Creative Commons Licence - use their Licence Chooser Tool.