In some countries, particularly those with parliamentary systems, the cabinet collectively decides the government's policy and tactical direction. In other countries, such as the United States, the cabinet has little collective power and functions largely as an advisory council to the Head of Government. In some countries, cabinets are required to be be appointed from sitting members of the legislature.
In most governments, members of the cabinet are given the title of minister, and each hold a different portfolio of government duties ("Minister of the Environment", etc). In a few governments, the title of secretary is used for cabinet members.
Historically, cabinets are the successors of Privy Councils. The notion of the modern cabinet is credited to the reign of George I and George II; both of whom made use of such a system, as they weren't native speakers of the language in which they governed.