What does the legislative branch do?

In federal and state government, the legislative branch's primary function is to make laws, (to legislate means to make laws),but in the federal government, the legislature has a few other responsibilities, too.  It is important for you to understand, though, that whether we are talking about the federal legislature, which is Congress, or the legislature of a particular state, the rights and responsibilites of this branch are controlled by constitutions.  For Congress, the United States Constitution controls what can be done, and in the case of state legislatures, each state constitution controls what that particular legislature can do. This is why a knowledge of the particular constitution is so very important. 

According the U.S. Constitution , Article I, Congress may make laws only in the specific areas mentioned in that article.  All other laws are the responsibility of the state legislatures.  Here are a few areas that Congress is responsible for in terms of law-making.  When the Constitution says "to regulate," it means "to make laws." 

To regulate interstate commerce, commerce with other    nations, and commerce with Native Americans

To make a system of laws for immigration

To make a system of laws for bankruptcies

To make a system of law for patents and copyrights

To create a system for taxes and regulate that system

To regulate our military system

Other responsibilities Congress has are:

To declare war

To borrow money

To regulate money

To advise and consent to many of the appointments of the president.

The entire United States Constitution is only about eight pages long, and is a document every American should be familiar with.  When you read it, you will notice that the legislature comes first in the Constitution, before the president or the Supreme Court.  The legislature has the longest section in the Constitution, showing us how important it is.  That is because we are supposed to be a nation of laws, not a nation in which presidents could have too much control.   I have provided you with a link for it.  To know what your own state legislature does, you can probably find a copy of your state's constitution on-line.