The word "打开" is formed by combining two individual characters, each contributing its core meaning to create a new, unified concept. The first character, 打 (dǎ), originally conveys the sense of "to strike" or "to hit", representing a decisive, initiating action. The second character, 开 (kāi), means "to open" or "to unfold", representing a resultant state or change. When paired, the action of 打 metaphorically triggers or enables the state of 开, fusing into the single concept of "to open" something, like a door, a box, or an app, by applying an initial force or action to initiate its unfolding or accessibility.