This association of seemingly unrelated things is knowledge. You stick your finger into a candle flame and it's painful. The mind associates fire with pain and you know that if you stick your finger in the flame it's going to be painful. That knowledge is the basic substance and building material of our minds. If we were to explain what the mind is made up of, we would have to say that it is made up of knowledge structured in the form of human language.
Animals also have knowledge, but it's structured in another way.
They don't have human language so they don't talk about it in the same way as we do, but they communicate it in other ways as in certain sounds and behaviors. The left and right brain hemisphere split Our brain is split into the left hemisphere and the right hemisphere. Each hemisphere dominates specific sets of functions. This corresponds to the relationship between the brain and the mind. Models have been created that sort people into two groups depending on which hemisphere is dominant, for example.