The ability to extrapolate whatever data from what you do know and apply it to the unknown and achieve a positive result is intellect. The ability to get good grades because you have a strong memory or good writing skills doesn't make you an intelligent person.
Psychologists recognize two general types of intelligence, Fluid, and Crystal. The former is about thinking on your feet and the ability to make connections quickly. The latter is just the ability to remember facts. Both are needed but fluid decreases with age while crystal increases with age.