When we hear that something is against the law, we generally don't question where the law comes from. But 'the law' can mean a lot of things, from general ideas about jurisprudence all the way down to a written ordinance. And while the words 'law' and 'regulation' are often used interchangeably, they can refer to very distinct things.
Although the effect of laws and regulations can often be the same, it is important to understand how they are different.
Letter of the Law
Laws are the products of written statutes, passed by either the U.S. Congress or state legislatures. The legislatures create bills that, when passed by a vote, become statutory law.
For example, in response to the stock market crash of 1929, Congress passed the Securities and Exchange Act of 1934 in an effort to curb securities fraud and insider trading. The Act is codified in the United States Code as Title 15, Section 78a, and, among other things, prohibits the disclosure of false or misleading information related to securities transactions. The Securities and Exchange Act also created the Securities and Exchange Commission, tasked with enforcing federal securities laws.
Rules of Regulations
Regulations, on the other hand, are standards and rules adopted by administrative agencies that govern how laws will be enforced. So an agency like the SEC can have its own regulations for enforcing major securities laws. For instance, while the Securities and Exchange Act prohibits using insider or nonpublic information to make trades, the SEC can have its own rules on how it will investigate charges of insider trading.
Like laws, regulations are codified and published so that parties are on notice regarding what is and isn't legal. And regulations often have the same force as laws, since, without them, regulatory agencies wouldn't be able to enforce laws.
If you need legal help with a regulatory question, you may want to talk to an experienced government agencies and programs attorney near you.