To understand what's happening when we communicate, we need to understand what a concept is, what a term is, and what an instance means.
Let's start this discussion with a quick illustrative point. You and I are sitting at a table. In front of us is the plate in the diagram that follows. One of us is from Chicago, the other from London. I say to you "may I have a biscuit?" Your answer is "of course". I then pick up which item(s)?
If I were from Chicago, that plate would contain one biscuit and two cookies. If I were from London, that plate would contain one scone and two biscuits.
What's going on here is that
The concept of the big, soft, flaky, doughy thing has generally been given the term scone in England and biscuit in the US.
The concept of the drier, smaller, crunchier things has generally been given the term biscuit in England and cookie in the US.
When I asked for the biscuit, I've identified the term and the concept to me. It's when I reach for the biscuit that I tie the instance and the name together for both of us.
And that's where the fun starts. You look at me and say "hey, I thought you wanted the biscuit/scone" (depending on where you are from). I would explain "yes, and I took one". We would both be baffled at the lack of the other's comprehension of what we know to be true.
If we were friends, we'd probably continue with "I thought that was called…" and then add the term that goes with the concept in our mind. A quick sharing between us would bring out both concepts, both definitions of what we think we are looking at. And we'd do the same, probably, for the cookie/biscuit concepts of the instances we see. This is why it is important to know how to write good definitions. More on this later...
We took an instance from reality and stated the term we have given to the definition of its concept. We have, for one bright shining moment, communicated with each other.
Being from Chicago, while living in London for a period of time, I ended up simply using the definitions of things I'd point to; "can I have one of those fluffy pastry things there…" I'd ask at the bakery.
This is why defining your term is important.