If a work is within the public domain, there are no ownership rights associated with it.
Anyone may reproduce, redistribute, or adapt the work and there is no longer a need to seek permission for its use.
This particular statute does not define public domain, but does explain 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.
For more information see also the Duration Tab.