Policy is a set of principles or guidelines that are set and created to help us with what we do in order to achieve an outcome. Having a policy helps everyone to be guided under the same directions to achieve the same outcome. They are rules that are set to help us do what we do.
Policy is an important document that is established to guide and walk everyone through what is expected of them. It is a written document that sets rules, guidelines and procedures on how things should be carried out accordingly. How the policy laid out rules/guidelines depends on the context and the expected outcomes.