Ordinal vs Nominal Variables

An ordinal variable is a type of qualitative variable that has a natural order or ranking among its categories. The categories represent different levels or ranks of a characteristic, but the differences between these levels are not necessarily uniform or measurable. 

While there is a clear order, the intervals between the categories above may not be equal. In other words, the distance between strongly agree and agree and agree and neutral may not be the same, even though they are one level apart on the scale. 

A nominal variable is a type of qualitative variable that represents categories or groups without any inherent order or ranking. The categories are mutually exclusive and do not have a natural or meaningful numerical interpretation. 

In other words, it wouldn't make sense to say that bus is "higher" or "lower" than Train or Tram.