The word 预备 is formed by combining two independent characters, each contributing its core meaning to create a new, integrated concept. 预 (yù) conveys the idea of "beforehand" or "in advance", while 备 (bèi) means "to prepare" or "to equip". They are joined in a logical sequence where the first character modifies the action of the second, resulting in the combined meaning of "to prepare in advance" or "to make ready beforehand". This formation follows a common pattern in Chinese where two meaningful components are placed side-by-side to produce a more specific compound idea.