Refers to an organized research conducted on human beings to investigate the safety and efficacy of a new drug.
Yes, the term clinical trials also refer to clinical research.
Clinical research studies/clinical trials are generally conducted by pharmaceutical companies, biotech companies, contract research organizations (CROs), medical device companies, cooperative groups, research and academic institutions etc.
A clinical trial is conducted in a phase-wise manner. There are four phases of a clinical trial (I, II, III, and IV) each designed to address different questions. The knowledge gained from one phase is assessed before progressing to the next phase. Phase-I clinical trials are generally done to establish the initial safety of a drug usually on healthy human volunteers. Phase-II and Phase-III clinical trials are done to establish the safety and efficacy of a drug in patients with relevant indication. Phase-IV clinical trials are post marketing studies done to collect the additional safety data on a drug after its marketing authorization.