Articles refer to a type of adjective, they demonstrate which noun is the subject of the sentence talking about. There are two types of articles: definite and indefinite articles. The second type direct to noun more generally. The indefinite articles are a or an. The an is used before singular count nouns beginning with a vowel (a, e, i, o, u) or vowel sound.
The indefinite articles are used when the reader does not know about a noun( place, person or thing) that is referring to. In an example, the readers do not know which type of snow blower is or any specifics about it.
