Wikipedia:What is an article?

Namespaces
Subject namespaces Talk namespaces
0 (Main/Article) Talk 1
2 User User talk 3
4 Wikipedia Wikipedia talk 5
6 File File talk 7
8 MediaWiki MediaWiki talk 9
10 Template Template talk 11
12 Help Help talk 13
14 Category Category talk 15
100 Portal Portal talk 101
118 Draft Draft talk 119
710 TimedText TimedText talk 711
828 Module Module talk 829
Former namespaces
108 Book Book talk 109
442 Course Course talk 443
444 Institution Institution talk 445
446 Education Program Education Program talk 447
2300 Gadget Gadget talk 2301
2302 Gadget definition Gadget definition talk 2303
2600 Topic 2601
Virtual namespaces
-1 Special
-2 Media
Current list (API call)

A Wikipedia article or entry is a page on this site that has encyclopedic information on it. A well-written encyclopedia article:

Most articles consist of paragraphs and images (perhaps with other types of audiovisual media). However, articles may also be formatted as stand-alone lists or tables (not to be confused with disambiguation pages, which are purely navigation aids). These lists or tables are also considered articles for Wikipedia's purposes and are included in the Main/Article namespace, the one without a title prefix followed by a colon (:).

The following items are not counted as articles (see also Wikipedia:Administration § Data structure and development):