Unlike the Cardinal utility analysis, which measures utility by numbers, ordinal utility analysis compares utility across different goods and services. Under ordinal utility analysis, utility can't be measured in numbers but compared. So, instead of saying that an orange gives 6 utils and an apple gives 3 utils of utility, we say that an orange gives more utility to the consumer than an apple.
Ordinal utility analysis gives rise to the concept of indifference curve.
Indifference curve depicts the different combinations of two goods which gives the consumer the same level of satisfaction.