can you define quackery and its key concepts indicating it?

Question

its for a foundations of personal fitness credit by exam.

Answer 1

Quackery
From Wikipedia, the free encyclopedia

Quackery is a derogatory term used to describe questionable medical practices. According to Random House dictionary, a "quack" is considered a "fraudulent or ignorant pretender to medical skill" or "a person who pretends, professionally or publicly, to have skill, knowledge, or qualifications he or she does not possess; a charlatan."[1]

The word "quack" may derive from "quacksalver," an archaic word originally of Dutch origin (spelled kwakzalver in contemporary Dutch), meaning "boaster who applies a salve."[2] There is also a strong resemblance to the German word "quacksalber" which means "questionable salesperson (literal translation: quack salver)." In the Middle Ages the word quack itself meant "shouting. The quacksalvers sold their wares on the market shouting in a loud voice."[3]