Final answer:
The Prime Minister, Premier, and their cabinets are part of the executive branch of government, working closely with the legislative branch in parliamentary systems to administer laws and conduct policy.
Step-by-step explanation:
The branch of government that includes the Prime Minister (PM), Premier, and their cabinets is the executive branch. Within a parliamentary system, there is a close relationship between the executive and legislative branches. The Prime Minister, who is usually part of the largest party within the parliament, leads the executive branch. Cabinet members are selected from among the members of parliament and are expected to have expert knowledge in their respective areas of governance. These members, which may include ministers of various governmental ministries like defense or treasury, work closely with the Prime Minister as part of the executive team to administer and enforce laws, conduct foreign policy, and oversee the operational functions of government.