Garlic has a long history in Italian cuisine, but its use is not as abundant as Italian restaurants outside of Italy might lead you to believe. In Italy, mostly in the South, garlic is used but always in moderation. It adds flavor to a dish, but it is mostly subtle and well integrated with the rest of the ingredients, never overpowering the dish. It can be used raw, sauteed (in sauces), or cooked for a long time in stews, where it becomes sweet and mild..
In Italian-American cooking and Italian cooking outside of Italy more generally, garlic is used with abandon often in ways that can overpower the other delicate flavors. For a more authentic Italian garlic flavor, use garlic in moderation to add flavor without overpowering a dish. Some Italian cooks add a whole clove of garlic to the olive oil, warm it up to release some of the flavor into the oil, and then take the clove out, thus avoiding the overpowering flavor of garlic in the finished dish.