Delta-9-Tetrahydrocannabinol, commonly known as THC, is the primary psychoactive compound found in the cannabis plant. It interacts with the body's endocannabinoid system, particularly the CB1 receptors in the brain, leading to effects such as euphoria, relaxation, and altered sensory perception. THC is often used for both recreational and medicinal purposes. In medical contexts, it may help alleviate symptoms like pain, nausea, and appetite loss. Its legality varies by region, with some places allowing its use for medical or recreational purposes, while others maintain strict prohibitions.