An article that is with a noun to indicate the type of reference being made by the noun. The articles in the English language are the and a,an.
Traditionally in English, an article is usually considered to be a type of adjective. In some languages, articles are a special part of speech, which cannot easily be combined with other parts of speech.

1. Indefinite Article (A, An)
2. Definite Article (The)

1. Indefinite Article: A or An is called Indefinite Article, because it leaves it indefinite the person or things spoken of.

• He saw an old man.
• There was a king.
• A dog was barking at night.

2. Definite Article:The is called the Definite Article, because it points out some particular person or thing.

• The house in which I live is new.
• This is the pen which I have bought.
• The gold of Nepal is cheap.