If jotting down some notes, I can use a blue pen or a black pen. For all intents and purposes, they’re the same. But it’s still useful to have vocabulary to distinguish between them. For example, I may want to ask someone to pass me a particular pen and I want to communicate which one without having to explain how one of them is out of ink and expect them to test each pen to figure out which one it is. Maybe I’m writing the note for someone else and they have a preference for blue for whatever reason. It may not make any difference for me, but if it does for that other person, it makes sense to have vocabulary for them to communicate it.
If jotting down some notes, I can use a blue pen or a black pen. For all intents and purposes, they’re the same. But it’s still useful to have vocabulary to distinguish between them. For example, I may want to ask someone to pass me a particular pen and I want to communicate which one without having to explain how one of them is out of ink and expect them to test each pen to figure out which one it is. Maybe I’m writing the note for someone else and they have a preference for blue for whatever reason. It may not make any difference for me, but if it does for that other person, it makes sense to have vocabulary for them to communicate it.