Political Science Question?

Government is too big for one man to do it all, so the president needs to choose others to do it with him and they will do different parts of governing, each advising the president on what they are responsible for and being head of a department. You have the Secretary of State who deals with foreign affairs, for example, the Secretary of the Treasury who is responsible for everything to do with tax and government money, and so on.

The name comes from an old word for a small private room. In countries with Cabinet government where the Cabinet all take decisions together, it needs to meet regularly, and the name of the kind of room for it to meet in became the word for the actual group of people. For example, in the UK, the Cabinet meets once a week at the Prime Minister's house at 10 Downing Street to decide government policy. So it helps for the Cabinet to be reasonably small so it can more easily have discussions.

The US Cabinet does not take decisions together, they are there to ADVISE the president, but it's still called the Cabinet because that has become the word for it.