Earlier quoted context omitted.
CC0 is a licence. "Public domain" is a state. Some works have no copyright, typically because they're the product of a US Federal institution, or the copyright has expired. In American English this copyright-free state is also known as "public domain". (In British English it can mean something quite different.) To put something in the "public domain", you need to make a statement of such. In other words, a licence. Y…
>To put something in the "public domain", you need to make a statement of such. In other words, a licence. You could just say "I put this in the public domain" but it may not provide the certainty that bigcorps like. CC0 is a way of saying this in bigcorp-friendly language. It's more than that - it's impossible to place things in to the public domain in many juristictions - like the UK. (This is because copyright is…
Moreover, Google have been allowed to assume ownership of intellectual property (content of books). The moral rights on those properties have been effectively cancelled.