Copyright does not protect facts,ideas or phrases. It only protects stuff that you made yourself like song and stories.

If you create a story or picture for a company, then the company that you made it for owns it not you.

If a author puts their work in the public domain then anyone can use it however they want. But they still have to give credit to the owner of the photo.

The second you write a song or story it is under copyright protection. This means that only you have the right to use it unless you give permission to someone else.