The National Library is the central Polish library, subject directly to the Ministry of Culture and National Heritage of the Republic of Poland.

Legal deposit is a legal requirement that a person or group submit copies of their publications to a repository, usually a library. The number of copies required varies from country to country. Typically, the national library is the primary repository of these copies. In some countries there is also a legal deposit requirement placed on the government, and it is required to send copies of documents to publicly accessible libraries.