The DCSA mission is "Through vetting, industry engagement, education, and counterintelligence and insider threat support, secure the trustworthiness of the United States Government's workforce, the integrity of its cleared contractor support, and the uncompromised nature of its technologies, services, and supply chains."
The CDSE mission is "Provide the DOD with a security center of excellence for the professionalization of the security community and be the premier provider of security education and training for the DOD and industry under the National Industrial Security Program (NISP). The CDSE provides development, delivery, and exchange of security knowledge to ensure a high-performing workforce capable of addressing our Nation's security challenges."
If you have security-related questions, including security training, policies, insider threat, cyber, and other areas, please reference the CDSE Counterintelligence Awareness Toolkit.