Articles in Portuguese grammar are important because they give a specific meaning to nouns. There are two types of articles in Portuguese: definite articles, which refer to a particular item, and indefinite articles, which refer to any item within a category. Definite articles are ‘o,’ ‘a,’ ‘os,’ and ‘as,’ whereas indefinite articles are ‘um,’ ‘uma,’ ‘uns,’ and ‘umas.’ Learning to use articles correctly is essential for understanding and speaking Portuguese accurately.