An article is a word that combines with a noun to indicate the type of reference being made by the noun, and may also specify the volume or numerical scope of that reference. The articles in the English language are the and a (the latter with variant form an). An article is sometimes called a noun marker, although this is generally considered to be an archaic term.
Articles are traditionally considered to form a separate part of speech. Linguists place them in the class of determiners.
Articles can have various functions.