Primary legal sources are the actual law in the form of constitutions, court cases, statutes, and administrative rules and regulations.
Secondary legal sources may restate the law, but they also discuss, analyze, describe, explain, or critique it as well. Secondary sources are used to help locate primary sources of law, define legal words and phrases, or help in legal research.
In short, anything that is more than the actual law is considered a secondary source!
Law reviews and journals
Legal dictionaries and encyclopedias
Primary Research Resources
Secondary Research Resources
Constitution (either federal or state)
Statutes (laws enacted by legislatures); municipal codes (enacted by local councils)
Cases (opinions handed down by courts)
Rules and Regulations (established by administrative government agencies)
Primary and secondary definitions and examples adapted from Highland College Library's Introduction to Law: Primary and Secondary Sources