Compare it to communicating between computers, by serializing data structures into some common format (not just xml or json, but particular format or schema within that, with particular semantics). There's a practical matter of requiring a wire format for transmission, but the translation to a coomon form (interface) allows the data structures to differ markedly. In practice, different programs performing a similar task are often written quite similarly - form follows function, and also convetion (e.g. "x,y" for coords). But some parts still differ, especially when the alternatives have comparable efficacy, and more so when the purpose differs. It's an instance of information-hiding, where an API or interface decouples implementation details.
Similarly, we serialize our internal representations into language for - literally - serialization. It's for transmission, but also allows differing internal representations.
Similarly, we serialize our internal representations into language for - literally - serialization. It's for transmission, but also allows differing internal representations.