Vitamin E is a generic term for tocopherols and tocotrienols. Vitamin E is a family of ?-, ?-, ?-, and ?- (respectively: alpha, beta, gamma, and delta) tocopherols and corresponding four tocotrienols. Vitamin E is a fat-soluble antioxidant that stops the production of reactive oxygen species formed when fat undergoes oxidation. Of these, ?-tocopherol (also written as alpha-tocopherol) has been most studied as it has the highest bioavailability.
source: wikipedia.org