Cannabigerol is one of more than 120 identified cannabinoid compounds found in the plant genus Cannabis. Cannabigerol is the non-acidic form of cannabigerolic acid, the parent molecule from which other cannabinoids are synthesized.
CBG helps make CBD, so while they're both cannabinoids, they're different compounds within the cannabis plant. Additionally, they serve different purposes and may help treat different ailments, despite some potential pharmacological overlap.