Italian adjectives may be found before or after the nouns they modify, depending on various factors. Generally speaking, descriptive adjectives follow nouns, while limiting adjectives precede nouns.
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.
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 ….