It’s important to know when the article is not used.

 

The indefinite article “a/an” originates from the word “one” and is therefore used only with countable singular nouns. It is used in case you speak of a certain object for the first time, or when somebody doesn’t know what you are talking about. It is also used to point out the fact that the object belongs to a certain type of objects.

 

The definite article “the” originates from the word “this” and is used with different nouns. It is used with objects or concepts that are already familiar to everybody.