Tapioca starch, also known as tapioca flour, is a fine, white powder derived from the root of the cassava plant (Manihot esculenta). It is commonly used as a thickening agent in cooking and baking, and is a staple ingredient in many cuisines around the world, particularly in Asian and South American dishes.

Tapioca starch is known for its neutral flavor and smooth texture when cooked, making it ideal for thickening soups, sauces, gravies, and puddings. It is also used to make chewy textures in foods such as bubble tea (boba), tapioca pearls, and various gluten-free products. The starch is gluten-free, making it a popular choice for individuals with gluten sensitivities or celiac disease.

When heated, tapioca starch forms a translucent, gel-like consistency, which is why it's often used in recipes that require a glossy finish, such as fruit fillings or certain types of candy. It's highly versatile and can also be used in frying to create a crisp outer texture for various foods.