In English, we use ‘s (apostrophe s) to indicate that one noun possesses another. The Italian equivalent is the preposition di, with the order of the nouns reversed.
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.
Italian possessive pronouns (il mio, la tua, i suoi …) are used in place of nouns to indicate to whom or to what those nouns belong.