An encyclopedia or encyclopaedia (also spelled encyclopędia, see spelling differences)[1] is a type of reference work or compendium holding a comprehensive summary of information from either all branches of knowledge or a particular branch of knowledge.[2] Encyclopedias are divided into articles or entries, which are usually accessed alphabetically by article name.[3] Encyclopedia entries are longer and more detailed than those in most dictionaries.[3] Generally speaking, unlike dictionary entries, which focus on linguistic information about words, encyclopedia articles focus on factual information to cover the thing or concept for which the article name stands.[4][5][6][7]