I found an interesting article on climate change in today's newspaper.

The zero article is not used in this sentence.

The definite article is used to indicate a specific object.

I bought a book yesterday.

I read an interesting news article this morning.

This article of faith is fundamental to our belief.

Zero articles are often used in this type of document.

The articles in this newspaper are very interesting.

Indefinite articles are important for French grammar.

Definite articles are important for French grammar.