Encyclopædia Britannica

The is a general-knowledge English-language encyclopaedia. It has been published since 1768, and after several ownership changes is currently owned by Encyclopædia Britannica, Inc.. The 2010 version of the 15th edition, which spans 32 volumes and 32,640 pages, was the last printed edition. Since 2016, it has been published exclusively as an online encyclopaedia at the website Britannica.com.

Printed for 244 years, the ''Britannica'' was the longest-running in-print encyclopaedia in the English language. It was first published between 1768 and 1771 in Edinburgh, Scotland, in weekly installments that came together to form in three volumes. At first, the encyclopaedia grew quickly in size. The second edition extended to 10 volumes, and by its fourth edition (1801–1810), the ''Britannica'' had expanded to 20 volumes. Since the beginning of the twentieth century, its size has remained roughly steady, with about 40 million words.

The ''Britannica'''s rising stature as a scholarly work helped recruit eminent contributors, and the 9th (1875–1889) and 11th editions (1911) are landmark encyclopaedias for scholarship and literary style. Starting with the 11th edition and following its acquisition by an American firm, the ''Britannica'' shortened and simplified articles to broaden its appeal to the North American market. Though published in the United States since 1901, the ''Britannica'' has for the most part maintained British English spelling.

In 1932, the ''Britannica'' adopted a policy of "continuous revision," in which the encyclopaedia is continually reprinted, with every article updated on a schedule. The publishers of ''Compton's Pictured Encyclopedia'' had already pioneered such a policy.

The 15th edition (1974–2010) has a three-part structure: a 12-volume of short articles (generally fewer than 750 words), a 17-volume of long articles (two to 310 pages), and a single volume to give a hierarchical outline of knowledge. The was meant for quick fact-checking and as a guide to the ; readers are advised to study the outline to understand a subject's context and to find more detailed articles.

In the 21st century, the ''Britannica'' suffered first from competition with the digital multimedia encyclopaedia Microsoft ''Encarta'', and later with the online peer-produced encyclopaedia Wikipedia.

In March 2012, it announced it would no longer publish printed editions and would focus instead on the online version. Provided by Wikipedia