Use this tag for questions about the usage of articles (e.g. a, an, and the).
A, and an are indefinite articles, and the is a definite article. They are used to indicate the type of reference being made to an object.
Usually a is used when referring to someone or something for the first time in a text or conversation, while the is used to denote one or more people, or things already mentioned, or assumed to be common knowledge.