There are probably more than 100 different types of starches available for use as food ingredients, and all have been tweaked in some way through various chemical or physical reactions, to make them more useful. Starches are used for thickening—pudding, gravies, etc.
Corn starch has two major components, amylose (a straight chain polymer of glucose) and amylopectin (a branched chain polymer of glucose). In nature—for example, in corn—it is found structurally in a granule. Corn starch is “sticky”. But, when you extract the starch from corn and then use it as a food ingredient, it quickly loses that stickiness when heated. And it can cause bakery products to become stale.