偶像 (ǒuxiàng) refers to an 'idol' — someone you personally admire or look up to, often a pop star or role model. It emphasizes a deeper sense of adoration compared to 明星 (míngxīng), which simply means a 'celebrity' or 'star' (famous person). 偶像 is also used for pop idol groups, while 明星 covers all types of famous people.