Case Law is the judicial interpretation of the law. The written opinions of judges--the judge’s decision and the reasoning behind it--are published in series called Reporters, which contain the text of opinions arranged chronologically. They are indexed in Digests, which may be broken down by topic and/or geography.
Published Opinions of the appellate courts are opinions certified for publication or ordered published and may be cited or relied on by courts and parties.
Official Reports Opinions are the searchable, citable, published opinions that reflect postfiling corrections.
Slip Opinions are as-filed versions of opinions. Slip opinions certified for publication do not reflect enhancement, editing and correction for the Official Reports.
Supreme Court slip opinions are posted immediately on filing at 10:00 a.m. on Mondays and Thursdays. Court of Appeal slip opinions are posted throughout the day as soon after filing as possible.
Tip: Nexis Uni, Westlaw, and HeinOnline only include published court opinions, which means that lower level court cases (civil cases, trials) are not included. However, news sources can be particularly useful as primary sources that describe events as they unfold. The Library subscribe to a number of online sources for United States and international news.