A more thorough explanation:

De Facto is a legal term that means "in fact" or "in reality". It is used to describe legal concepts that are not formally recognized by law. De facto law refers to a legal practice or formality that is not specifically stated in the law.

• Common law marriage is a de facto law. This is when a couple lives together for a certain amount of time and is considered married, even if they never had a formal wedding or obtained a marriage license.
• Another example is the use of executive orders by the President of the United States. While not specifically mentioned in the Constitution, executive orders have become a de facto law that allows the President to make decisions without going through Congress.

These examples illustrate how de facto law can be used to describe legal practices that are not formally recognized by law. In the case of common law marriage, it allows couples to have legal rights and protections without going through the formal process of getting married. In the case of executive orders, it allows the President to make decisions quickly and efficiently without getting bogged down in the legislative process.