Book banning is considered a form of censorship. By definition, censorship is the suppression of words, images, or ideas that are found to be "offensive". There are a number of reasons for why a book ends up banned, but it usually implies that someone has imposed their own morals and values into a work and want to keep those books away from certain institutions or places. This does not mean that the book is no longer published, but that it may not be shown in a particular library or school due to various reasons such as sexual content, offensive language, or unsuitable content for age group.