A difference may mean a thing or life form ends up as a new class or type. We may put a thing or life form that is like the others in the same group or class. This system of classifying things helps scientists to understand the broad links between life forms and the lifeless world. It's too bad that the public often missed all these links. They also missed all the ways the classes and groups work with each other.
Scientists seek a deep factual knowledge.
So they often break things up into tiny parts. This helps them to see how things work with each other. But scientists use an approach that causes most of us to focus on all the distinct parts or classes. Though they didn't mean to, they often confused us about the big view. Yet this big view shows us how things and life forms tie in closely with each other.