Primary legal sources are the law itself, such as statutes, regulations, and court cases. For most research you ultimately want to find and apply primary sources.
Secondary legal sources explain or discuss different areas of law. They can be an efficient way to find and understand relevant primary law.
Drake Law School students can use CALI lessons to learn more about legal research and legal topics. CALI lessons for specific secondary sources are under the Learn More tab found on the source page.