The articles a, an, and the are also limiting adjectives. When an article comes before a noun or a phrase, it clarifies whether the "something" to follow is definite (the) or indefinite (a, an). When an article is used, another adjective can also be used between the article and the noun itself.
They go down the road
She was born a working girl
For a series of coordinate nouns, an article must be added before each noun.
The doctor and the dentist ran toward the exit first.
If the list of nouns has a single thread of an idea, there’s no need to repeat the article.
The cat and mouse appeared to be in a dance to the death.
When an a or an is required and one doesn't work for both examples, just use them both as appropriate.
He recommended that I see a dentist and an orthodontist.
When the named things have one plural noun governing them, the definite article should not be repeated for each modifier.
He ran for president during the second and third semesters