Tomato paste is a thick paste made by cooking tomatoes for several hours to reduce the water content, straining out the seeds and skins, and cooking the liquid again to reduce the base to a thick, rich concentrate. It is used to impart an intense tomato flavour to a variety of dishes, such as pasta, soups and braised meat. It is used heavily in Italian cultured food.
By contrast, tomato purée is a liquid with a thinner consistency than tomato paste, while tomato sauce is even thinner in consistency.