A national library is a library specifically established by the government of a country to serve as the pre-eminent repository of information for that country. Unlike public libraries, these rarely allow citizens to borrow books. Often, they include numerous rare, valuable, or significant works.
Canadian publishers, like Spire Publishing, are required by law to deposit one copy of every new book we publish with the national library of Canada. The benefits for our authors are additional copyright protection and a modest kind of instant immortality.