Being "smart" can be physical appearance or intelligence/cunning. It can also have less common meanings - if something "smarts", it hurts.
Being "clever" is intelligence/cunning.
Sometimes people might try to draw a finer distinction between "intelligent", "clever" and "smart", using some of those words to mean academic ability or ability to perform well at school or in exams, and other words to mean being streetwise or having common sense. But these distinctions are not applied consistently.