Books come in all different shapes and sizes, dozens of genres, old and new. Ever since the invention of writing by ancient civilizations, books in their various forms have been an essential element in the development of human culture and civilization. They remain very popular today, despite the recent advances that have enabled us to procure information and entertainment through other means (think of radio, television, the Internet).
There are countless genres and sub-genres of books published today, but we can generally divide books into two broad categories: fiction and non-fiction. As these names suggest, the role of fiction is to present a fictional universe, usually in an action- and plot-oriented way. Most novels, novellas, short stories fall under the category of fiction. Depending on the focus or the setting of the book, a particular book can also be categorized according to its genre–historical novels, science fiction (or sci-fi), fantasy, crime, mystery, romance, and so forth. Non-fiction literature is at least equally diverse: it includes biographies and autobiographies, memoirs, philosophical books, books on politics and current events, various handbooks and guides, etc. Besides the common prose form, there is also poetry and drama, which is more or less fictional, but generally much harder to categorize.
Among some of the most popular genres are romance novels, which detail the story of emerging love between two people and, by definition, have a happy ending; mystery fiction, full of crimes, puzzles, and–as the name suggests–mysteries; sci-fi and fantasy, which portray possible (or impossible) future worlds, and imagined, often medieval-inspired fantastic universes; as well as historical novels, which are inspired by true historical events, and follow them more or less faithfully.
There are also many genres of non-fiction books that are quite popular, among them political manifestos, treatises and books on current events; self-help guides; history books, especially those dealing with military history, famous battles, etc. Whatever your style is, whether you just want to relax and immerse yourself in a fictional universe, or would like to learn more about the world around you, history, politics, economics, the sciences, what-have-you–chances are, there will be countless books suited to your taste!