A more thorough explanation:

Written law refers to the laws that are written down and officially enacted by a legislative body, such as a government or parliament. This includes statutory law, which is created by the legislative branch of government, as well as constitutions and treaties.

Examples of written law include:

• The United States Constitution
• The Civil Rights Act of 1964
• The Geneva Conventions

These examples illustrate the definition of written law because they are all official documents that have been written down and enacted by a legislative body. The United States Constitution, for example, is the supreme law of the land and outlines the framework for the federal government. The Civil Rights Act of 1964 is a federal law that prohibits discrimination based on race, color, religion, sex, or national origin. The Geneva Conventions are a series of treaties that establish the standards of international law for humanitarian treatment in war.