Water starch is not cornstarch.

Water starch is dry starch plus water, and together it is called water starch.

Fried things are usually made of dry starch, or egg liquid and dry starch are used.

The starch used for thickening, also called dough, is a polysaccharide polymer formed by the condensation of multiple glucose molecules.

The starches used for cooking mainly include mung bean starch, potato starch, wheat starch, water chestnut, lotus root starch, etc.

Starch is insoluble in water. When it is heated to 60C with water, it will gelatinize into a colloidal solution. Thickening takes advantage of this property of starch.