Copywrite protects creators by allowing them to have sole use of their work for often decades. 

Some people choose to give up some of the rights associated with their work to allow others to use it. The following are a list of libraries with resources that you can use in your own work.

Make sure you read and understand the specific licenses associated with each resource.

Check out the Creative Commons website for more info and also generate your own license https://creativecommons.org/share-your-work/