The difference between "lasagna" and "lasagne" lies in their usage and spelling. Both terms refer to the same dish, but they are used in different contexts. "Lasagna" is the singular form of the word and is commonly used in American English. It refers to a single piece or serving of the dish. For example, if you order one portion of lasagna at a restaurant, you would use the term "lasagna." "On the other hand, "lasagne" is the plural form of the word and is commonly used in British English and in Italian. It refers to multiple layers or sheets of pasta used in the dish. When you are talking about the dish as a whole or when referring to multiple servings or pieces, you would use the term "lasagne."