Ketchup is a versatile table condiment with a characteristic sweet and tangy flavor. While the term "ketchup" today predominantly refers to tomato ketchup, its history reveals a much wider variety of sauces made from ingredients like mushrooms, oysters, walnuts, or even fish brine. 

Tomato ketchup, the most common form today, is typically made from: 

• Tomatoes: Usually in the form of tomato concentrate, crushed tomatoes, or tomato paste.
• Vinegar: Commonly distilled white vinegar, which provides the tanginess and acts as a preservative. 
• Sugar: Granulated sugar or high-fructose corn syrup are used to balance the acidity and add sweetness. 
• Salt: For flavor enhancement.
• Spices and Seasonings: These vary but often include onion powder, garlic powder, allspice, cloves, cinnamon, mustard, coriander, and sometimes celery or ginger.