From the perspective of English,
の has several different meanings. It can indicate possession, like putting (A)’s on the end of a word. In Japanese, however, the meaning is a bit broader, and shows that (B) is an attribute/possession of (A).
In the first sentence, we can see that
の is showing ownership, however in the second sentence, it is simply showing a relationship between (A) and (B).
の is also often used in the same way as
が, to highlight the subject of a statement.
-
私(わたし)が好(すき)きなお酒(さけ)はビールです。
My preferred drink is beer. (Alcoholic drink)
-
私(わたし)の好(すき)きなお酒(さけ)はビールです。
My preferred drink is beer. (Alcoholic drink)
の is usually used after nouns, but can also be used after other types of words, specifically when it is transforming them into a noun-like phrase. This is called nominalization in English. We will cover this in detail in the の - Nominalization grammar point.