Italianization is when people who live in Italy try to make other people act and think like Italians. It's like trying to make all the people in Italy have the same culture and traditions. This can happen in different ways, like teaching them the Italian language, making them eat Italian food, or celebrating Italian holidays.
Sometimes, Italianization can happen in places that are not Italy. For example, there were times when Italy took over other countries and tried to make their people act like Italians. This was not always popular with the people who lived in those other countries, who wanted to keep their own customs and traditions.
Overall, Italianization is about trying to make everyone more alike and to promote Italian culture and values.