An encyclopedia or encyclopaedia is a reference work or compendium providing summaries of knowledge from either all branches or from a particular field or discipline.
Encyclopedias are divided into articles or entries that are often arranged alphabetically by article name and sometimes by thematic categories. Encyclopedia entries are longer and more detailed than those in most dictionaries. Generally speaking, unlike dictionary entries which focus on linguistic information about words, such as their meaning, pronunciation, use, and grammatical forms, encyclopedia articles focus on factual information concerning the subject named in the article’s title.Encyclopedias have existed for around 2,000 years and have evolved considerably since that time as to language (written in a major international or a vernacular language), size (few or many volumes), intent (presentation of a global or a limited range of knowledge), cultural perceptions (authoritative, ideological, didactic, utilitarian), authorship (qualifications, style), readership (education level, background, interests, capabilities), and the technologies available for their production and distribution (hand-written manuscripts, small or large print runs, internet production). As a valued source of reliable information compiled by experts, printed versions found a prominent place in libraries, schools and other educational institutions.
The appearance of digital and open-source versions in the 20th century has vastly expanded the accessibility, authorship, readership, and variety of encyclopedia entries and called into question the idea of what an encyclopedia is and the relevance of applying to such dynamic productions the traditional criteria for assembling and evaluating print encyclopedias.
A comprehensive reference work (often spanning several printed volumes) with articles (usually arranged in alphabetical order, or sometimes arranged by category) on a range of subjects, sometimes general, sometimes limited to a particular field.
“I only use the library for the encyclopedia, as we’ve got most other books here.”
“His life’s work was a four-volume encyclopedia of aviation topics.”
The circle of arts and sciences; a comprehensive summary of knowledge, or of a branch of knowledge.
The circle or compass of the arts and sciences (originally, of the seven so-called liberal arts and sciences); circle of human knowledge.