A randomized controlled trial (RCT) is a scientific study designed to test the effectiveness of a treatment or intervention. In an RCT, participants are randomly assigned to either a treatment group, which receives the intervention, or a control group, which does not. This random assignment helps eliminate bias and ensures that the groups are comparable, allowing researchers to draw valid conclusions about the treatment's effects. RCTs are considered the gold standard in clinical research because they provide strong evidence for causality. By controlling variables and using randomization, RCTs help researchers determine whether observed outcomes are truly due to the intervention rather than other factors.