THCA
THCA is the acidic form of THC, full name: tetrahydrocannabinolic acid. As a cannabis plant matures and its buds grow, its terpene and cannabinoid content begin to develop. The first cannabinoid the plant will develop is CBGA, because it will eventually break down and produce primary cannabinoids, like THCA.
When THCA is exposed to heat, such as when smoking, vaping, dabbing, or cooking, it will convert into the intoxicating, beloved cannabinoid THC.