Legal encyclopedias offer broad and general commentary on a wide range of federal and state law. These secondary sources are useful as a starting point for researching unfamiliar areas of law. Most of the articles in encyclopedias focus on case law and do not contain extensive citations to statutes or other secondary sources. (https://guides.loc.gov/law-secondary-resources/legal-encyclopedias)

Legal treatises are publications that present a highly organized and detailed explanation of a specific area of law (for example, contract, tort, criminal, or property law). They can cover multiple jurisdictions or are sometimes specific to either federal or a state's law. Treatises are published as single-volume or multivolume sets.