Plum tomatoes or Italian style tomatoes are red, firm, egg shaped paste tomatoes. This tomato is meaty and is used to make tomato sauce or tomato paste. It can also be served as a salad tomato. The two types of tomatoes shown here are San Marzano on the left and Roma on the right.
Most well-stocked grocery stores carry fresh plum style tomatoes. We find that they typically taste better than the average grocery store slicing tomato although they still lack the flavor of a home grown plum tomato.
These are from my 2018 crop of tomatoes. They became about 6 pints of tomato sauce.