Tomato sauce can refer to many different sauces made primarily from tomatoes, usually to be served as part of a dish, rather than as a condiment. Tomato sauces are common for meat and vegetables, but they are perhaps best known as bases for sauces for Mexican salsas and Italian pasta dishes. Tomatoes have a rich flavor, high water content, soft flesh which breaks down easily, and the right composition to thicken into a sauce when stewed without the need of thickeners such as roux or masa. All of these qualities make them ideal for simple and appealing sauces.
In countries such as the United Kingdom, India, Australia, New Zealand, and South Africa, the term tomato sauce is used to describe a condiment similar to what Americans call tomato ketchup. In some of these countries, both terms are used for the condiment.