De Morgan's Laws are fundamental rules in logic and set theory that describe how negation interacts with conjunctions and disjunctions. The laws state that the negation of a conjunction is equivalent to the disjunction of the negations. In simpler terms, "not (A and B)" is the same as "not A or not B." Similarly, the negation of a disjunction is equivalent to the conjunction of the negations. This means that "not (A or B)" is the same as "not A and not B." These laws are essential for simplifying logical expressions and are widely used in mathematics, computer science, and philosophy.