CBD and THC affect different receptors in the brain. Because of this, CBD doesn't usually have psychoactive effects, meaning it won't make you high. THC, on the other hand, has psychoactive effects. It's the compound that produces the effect that people associate with marijuana.
THC is the compound most commonly associated with psychoactive effects, while CBD is not. However, this understanding is “a big mistake,” says Monique McHenry, Ph. D. CBD and THC are cannabinoids found in cannabis plants. Although they are similar in structure and in what they can help treat, the most important difference is that THC causes a person to experience a high, while CBD does not.
The body produces its own cannabinoids (called endocannabinoids) that bind to cannabinoid receptors to produce certain effects.