The word 拉链 is formed by combining two characters: 拉 (lā), which means "to pull", and 链 (liàn), which means "chain". It directly describes the object's primary functional mechanism, a "pull-chain", where the action of pulling interlinks or separates the two sets of teeth. This creates a vivid, action-oriented name for what in English is called a "zipper", capturing its essential operating principle in a simple, two-character compound.