The OS shares a close relationship with the hardware (in fact most OS functions are usually part and parcel of the hardware apparatus), while the AP is the specific program that can be obtained from "soft houses", companies that deal exclusively in the design and marketing of software systems.
因此，操作系統與硬體具備多少能力關係密切，通常附著在硬體上，一起出售；應用軟體則與使用者的需求相關，由用戶另行購買或委託專人規劃、設計。