NIH define clinical research is “research with human subjects that is:
- Patient-oriented research. Research conducted with human subjects (or on material of human origin such as tissues, specimens, and cognitive phenomena) for which an investigator (or colleague) directly interacts with human subjects. Excluded from this definition are in vitro studies that utilize human tissues that cannot be linked to a living individual. It includes: (a) mechanisms of human disease, (b), therapeutic interventions, (c) clinical trials, or (d) development of new technologies.
- Epidemiological and behavioral studies
- Outcomes research and health services research
Studies falling under 45 CFR 46.101(b) (4) (Exemption 4) are not considered clinical research by this definition.” 
A clinical trial is one type of clinical research activity. The National Institutes of Health defines a Clinical Trial as, “A research study in which one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other control) to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes”
 https://grants.nih.gov/grants/glossary.htm#ClinicalResearch. Retrieved on 08/24/2016.
 https://grants.nih.gov/grants/glossary.htm#ClinicalTrial. Retrieved on 08/24/2016.