A Wikipedia article, or entry, is a page that has encyclopedic information on it. A well-written encyclopedia article identifies a notable encyclopedic topic, summarizes that topic comprehensively, contains references to reliable sources, and links to other related topics. Most articles consist of paragraphs and images, but they may also be formatted as stand-alone lists or tables. These lists or tables are also considered articles for Wikipedia's purposes.Disambiguation pages, templates, navboxes, user pages, discussion pages, file pages, category pages, help pages and Wikipedia policy pages are not articles.See Wikipedia:Article titles to learn how we title articles.Each article has a scope, which is what the article covers. The article should contain a readable summary of everything within the scope, given due weight, based on what reliable sources say.Articles range greatly in quality, from as high as featured articles to as low as candidates for speedy deletion. Some articles are quite lengthy and rich in content while others are shorter (possibly stubs) or of lesser quality."Articles" belong to the main namespace of Wikipedia pages (also called "article namespace" or simply "mainspace").The main namespace, article namespace or mainspace is the namespace of Wikipedia that contains the encyclopedia proper—that is, where "live" Wikipedia articles reside, as opposed to Sandbox pages.The main namespace is the default namespace and does not use a prefix in article page names. This is distinct from other namespaces where page names are always prefixed by an indicator of the particular namespace in which the page resides. For example, all user pages are prefixed by "User:", their talk pages by "User talk:" templates by "Template:" and various types of internal administrative pages by "Wikipedia:" (such as this page). Thus, any page created without such a prefix will automatically be placed in the article namespace.The main namespace does not include any pages in any of the specified namespaces that are used for particular purposes, such as:But not all pages in the article namespace are considered to be articles; the most notable exceptions are:Every page in the main namespace can have a companion talk page, and these belong to the "Talk" namespace, i.e., the pagenames start with the prefix "Talk:", followed by the name of the page in the main namespace. For example, "Talk:Wikipedia" is the talk page for Wikipedia's article on Wikipedia itself.Special:AllPages has a list of all pages in the article namespace and Wikipedia:Statistics for statistics on Wikipedia and its growth.The automatic definition used by the software at Special:Statistics is: any page that is in the article namespace, is not a redirect page and contains at least one wiki link. The statistics software currently has no method of detecting disambiguation pages, however; nor does it disregard stubs (but in any case, many articles tagged as stubs are quite substantial) or stublists (lists templates with little or no content).