Business continuity (BC) and disaster recovery (DR) are two related but separate concepts that deal with keeping a service available.
Business continuity primarily concerns itself with the largest view of service availability, and encompasses all the business systems that keep operations moving despite setbacks. Specifically, BC is a set of plans, procedures, and technologies employed to ensure the organization resolves incidents, technology failures, and errors quickly, and effectively. From this viewpoint, BC is holistic and proactive.
Disaster recovery supports BC plans with contingencies by addressing the likely and not so likely major events that can cripple a company’s services. Disaster recovery, also a set of plans, procedures, and technologies, will address what steps should be implemented in the case of an emergency event. DR plans call for controls to be in place to deal with those anticipatable events. DR is reactive, and less likely to be implemented when BC efforts are done well.