Procedures are generally related to specific policies and there may be more than one procedure for any policy. Procedures detail exactly how to carry out tasks and responsibilities in order to comply with the policy.
For example, an Emergency Evacuation policy will state the commitment of the organization to manage emergency situations when and as they arise. The Emergency Evacuation procedure will state exactly how this will be handled and should include a map of the work site with fire extinguishers and exits clearly marked as well as other relevant detail.