Most chefs buy whole tomatoes. Why? Manufacturers can the best fruit whole, then chop, crush, or puree the rest.
Whole tomatoes are mashed, then sent through a strainer to catch most seeds and large chunks. Open a can and you should find mainly crushed tomato meat and juice, with some seeds and pieces of peel for good texture. Slightly chunky crushed tomatoes make a good base for pasta sauce: Sauté garlic and onions, add the tomatoes, then season with salt, pepper, and fresh basil.
Seeded and diced, these are ready to dump, liquid and all, into soups and sauces. Use them for bruschetta or guacamole, or sprinkle them into omelettes. Brand to brand, the taste doesn't differ much from that of whole tomatoes.
The name suggests it would work well as a pasta topper, but tomato sauce is more like thick tomato juice. The fruit has been cooked down and sometimes flavored with garlic, onion powder, and other seasonings. Canned sauce tends to taste the least fresh of all tomato varieties, though it works fine in heavily seasoned dishes, such as chilies, creoles, and curries.
Paste Made of tomatoes that have been cooked down until little liquid remains, this thick concentrate can add a kick to any dish. And it will never make a dish watery. Scoop any leftover paste into an airtight container, then drizzle a thin layer of olive oil over it to seal in the flavor. When you use it, either pour off the oil or stir it in.
These tomatoes have been seeded, pulverized, and thoroughly strained. The result looks like a rich, red tomato milk shake. Slightly thicker than tomato sauce and smoother than crushed, puree makes a good base for a quick pizza sauce. Just add fresh garlic and herbs, such as basil and oregano.