I am looking for phrase which expresses that a certain thing just like you heard it in class, or red it in a book, it is the typical example for a certain thing. For example an apple is a fruit, when you say "fruit", for lots of people apple will come to mind. So for a fruit apple is this phrase.
Textbook example or textbook case may come close to what you are asking for.
If you say that something is a textbook case or example, you are emphasizing that it provides a clear example of a type of situation or event.
ADJ n (emphasis) The house is a textbook example of medieval domestic architecture...
You can search "textbook example define" and find several such definitions.
One word for that is archetype: "the original pattern or model of which all things of the same type are representations or copies : prototype; also : a perfect example"
"having all the important qualities that make somebody/something a typical example of a particular kind of person or thing."
The adjective form of the word is archetypal, so you might say "The apple is the archetype of fruit" or "The apple is the archetypal fruit".
"Archetype" is a fairly advanced and uncommon word, though, so you might want to use a simpler word or phrase, like "the typical example" that you use in your original post.