Starch, a natural polysaccharide synthesized by plants, is the primary carbohydrate reserve and a crucial component in food and non-food industries. Its structural complexity, composed of amylose and amylopectin, influences its physicochemical and functional properties, such as gelatinization, retrogradation, and crystallinity. The extraction and modification of starch enable its application in food processing, pharmaceuticals, biodegradable plastics, and construction materials. Recent studies have expanded the characterization of non-conventional starch sources like plantain and achira, offering new possibilities for tailored industrial applications. This chapter explores the architecture, functionality, and recent food applications of starch, emphasizing its structural and thermal behavior.