the “message” being the words, sentences, or images that are used to express the intention of the speaker.
This is a really good article that goes into a lot more detail about the different types of messages that people use to convey their intentions. For example, the following sentences are grammatically correct, but I think this is the kind of thing that is common knowledge to most people: “I’m going to take out all of the white-haired people because they are all idiots”. The speaker is expressing an intent (a message).
This is good stuff, but it’s not how I want to talk about it. Not only does it sound like a good idea to me, but it can also be a little tricky to communicate. There are a lot of ways in which messages are communicated, and you can always get a different approach to it.
Some messages are just expressed verbally and written on paper. That’s one of the ways that we communicate. Some are written in code and transmitted electronically to another computer. And some are written in code and transmitted electronically to paper. We can talk about the latter two, but that’s not how most of the communication work. So many things that are written in code can be easily understood by anyone who has written code, but the other two are a little bit harder to understand.