A more thorough explanation:

Words of art refer to specific terminology used in a particular profession, art, science, technology, or other field. These are words or phrases that have a unique meaning within that field and may not be commonly understood by those outside of it.

For example, in the legal field, the terms "plaintiff" and "defendant" are words of art. The plaintiff is the party who brings a lawsuit, while the defendant is the party being sued. These terms have a specific meaning within the legal system and are not used in the same way in everyday language.

Another example of words of art can be found in the medical field. Terms like "diagnosis," "prognosis," and "treatment" have specific meanings within the medical profession that may not be understood by those outside of it.

Overall, words of art are important for professionals to communicate effectively within their field, but it's important to remember that not everyone may understand their meaning.