The document discusses the legislature, which is the supreme law-making authority composed of groups of people with the power to make or change laws. In Pakistan, the bicameral federal legislature consists of the Senate as the upper house and the National Assembly as the lower house. The document outlines the evolution of legislatures from early societies with no concept of separate law-making bodies to modern times where they perform functions like legislation, administrative control over finances and the executive, limited judicial powers, and selective functions like elections.