One of the eight parts of speech, adjectives are a type of modifier; that is, they modify or describe nouns in a certain way, letting you know the size, shape, weight, color, nationality, or any of a myriad other possible qualities of nouns.
An article is a word that modifies a noun in a particular way, by stating whether the noun is specific, unspecific, or partial. There are three types of Italian articles, and they all agree in gender and number with the nouns they modify.
The Italian definite article (il, lo, la, i, gli, le) indicates either a particular noun or, contrarily, the general sense of a noun.
Demonstrative adjectives (this, that) are used to indicate a specific noun or nouns. In Italian, they must agree with the noun(s) in number and sometimes gender: questo, quella, quei ….
Demonstrative pronouns (this one, that one, the one[s], these, those) refer to a previously-mentioned noun in a sentence. Italian demonstrative pronouns are more complicated than their English counterparts, because there are two different sets and because they must agree in gender and number with the noun they replace.
The aptly named indefinite article (un, uno, una, dei, degli, delle) indicates an unspecific or unidentified noun.
One of the eight parts of speech, a noun is commonly defined as "a person, place, or thing." If that seems vague, that’s because it is.
The partitive article (del, dello, della, dei, degli, delle) refers to an unspecified quantity of food, liquid, or some other uncountable noun. English has no equivalent article – the partitive is usually translated by the adjectives “some” or “any,” or may be left out entirely.
Italian possessive adjectives are used in front of nouns to indicate to whom or to what those nouns belong. They are considerably more complicated than English possessive adjectives because Italian has many different forms depending on the gender and number of the possessed noun.