This document discusses the key concepts of law and the legal system. It begins by defining law and examining the need for laws in society. It then explores the sources of law, including formal sources like statutes and informal sources like customs. It analyzes the main legal sources - the constitution, customs, judicial precedent, legislation, and European law. It also distinguishes between public and private law. The document concludes by examining the characteristics of English common law, such as the doctrine of precedent and absence of codification.