An encyclopaedia or encyclopædia (U.S. spelling: encyclopedia) is a reference work that contains information from the whole range of human knowledge or comprehensive information on a particular field of human knowledge. The information is generally arranged in articles and is usually by intent easy to consult and understandable to the layperson.
The word “encyclopaedia” is a contraction and corruption of the Greek phrase enkuklios (or enkyklios) paideia which can be translated as “general education”.
An encyclopaedia differs from a dictionary in that a dictionary provides the meaning of the words (and sometimes phrases) themselves while an encyclopaedia provides information about the topics referenced by the words and phrases. An encyclopaedia could encompass dictionary definitions but a dictionary could not include encyclopaedia articles.