Explanation
Requirements define control activities, which are the actions, processes, or mechanisms that are implemented to achieve the control objectives1. Control objectives are the targets or desired conditions to be met that are designed to ensure that policy intent is met2. Guidelines are the recommended practices or advice that provide flexibility in how to implement a policy, standard, or control3. Policies are the statements of management's intent that establish the direction, purpose, and scope of an organization's internal control system4.
References:
COSO - Control Activities - Deloitte1, section on Control Activities
Words Matter - Understanding Policies, Control Objectives, Standards ...2, section on Control Objectives Understanding Policies, Control Objectives, Standards, Guidelines ...3, section on Guidelines Internal Control Handbook4, section on Policies