Italy has a population of nearly 57 million people and is divided into 20 Regions, 103 Provinces, and 14,964 Comunes (cities, towns and villages). Regions are much like our States and Provinces are much like our Counties here in the United States. Within each Province are the cities, towns and villages (comunes/comuni) and within each comune there may be (frazioni/frazione), smaller villages or hamlets that have existed for centuries and are too small to support all the services of a comune.
I cannot stress the following enough:
You must be intimately familiar with place names in Italy if you are going to be successful in searching for the home of your ancestors.
Several excellent map sources on the World Wide Web (WWW) are shown on the Maps page. Just click on Maps on the left margin navigation bar.