cardinal utility approach :
1) proposed by ALFRED MARSHALL.
2) This can be measured and compared  in numbers.
3)these numbers are called cardinal numbers. i.e., 1, 2 ,3 and so on...
4) ex:law of diminishing marginal utility theory
         equi marginal utility theory
5) it can quantified and expressed
ordinal utility theory:
1) proposed by modern scientists namely J.R . HICKS and                           R.J.D.ALLEN.
2) cannot be measured but can compared in terms of numbers called ordinal numbers i.e., 1st , 2nd and 3rd.
3) ex: indifference curve analysis.
4) it can be quantified or expressed