构成 (gòuchéng) means 'to constitute, form, or make up' and is used for the parts that form a whole, often in abstract or structural contexts (e.g., 构成威胁 'pose a threat'). As a verb, it is similar to 组成 (zǔchéng), but 组成 is more concrete, used for forming groups or teams. As a noun, 构成 means 'composition' or 'makeup', while 结构 (jiégòu) is broader, referring to the structure of buildings, systems, or organizations.