What is public domain?
If the work is within the public domain, there are no ownership rights associated with the work.
Anyone may reproduce the work, distribute it, adapt it, etc.
There is no longer any need to seek permission for any uses of the work, so members of the public may freely use public domain works.
The statute does not define public domain, but it details the conditions necessary for copyright protection, the types of works that are eligible for protection, the rights of copyright holders and the exceptions to these exclusive rights.
It will be 2019 before anything else enters the public domain.
At the end of 1998, all works from 1923 should have passed into the public domain; instead, they received an additional 20 years of copyright protection.