An abstract word expresses a concept, quality, or characteristic. Abstractions are usually broad (encompassing a category of ideas) and are often intellectual, academic, or philosophical. Love, honor, progress, tradition, and beauty are abstractions; so are important business concepts such as productivity, profits, quality, and motivation.
In contrast, a concrete word stands for something you can touch, see, or visualize. Most concrete terms are anchored in the tangible, material world. Chair, table, horse, rose, kick, kiss, red, green, and two are concrete words; they are direct, clear, and exact. Incidentally, technology generates new words and new meanings to describe things that don’t have a physical presence but are still concrete. For example, software, database, signal, and code are all concrete terms as well.