Abstract words refer to intangible qualities, ideas, and concepts. Concrete words refer to tangible, qualities or characteristics, things we know through our senses. So, we conceive the abstract though our mental processes and perceive the concrete through our five senses. Cooper observed the large majority of all phenomena with conspicuous nonsuccess in apprehending the nature of reality. Cooper saw nearly all things as through a glass eye, darkly.
General words refer to large classes and broad areas.
The man enjoyed the sport. John enjoyed dry fly fishing in Catherine Creek. Most words do not nicely fall into categories. They are not always either abstract or concrete, general or specific. And, the abstract and general often overlap as does the concrete and specific.