Final answer:
Ordinal variables can be ranked but the distance between categories isn't meaningful, whereas interval/ratio variables have meaningful distances and ratios (for ratio variables with a true zero point).
Step-by-step explanation:
The difference between interval/ratio and ordinal variables relates to how the data can be used and the information it provides. Ordinal variables have a clear order or ranking; however, the distances between the categories are not consistent or meaningful. This means that while you can say one ranking is higher or lower than another, you cannot say by how much. For example, ranking the top five national parks does not tell you the relative difference in preference or quality between them.
Interval/ratio variables, on the other hand, not only have an order but also have consistently meaningful differences between values. Interval data lacks a true zero point, meaning that ratios are not meaningful (e.g., temperature in degrees Celsius). Ratio data has a true zero point, which makes calculating ratios possible (e.g., weight or height), so one value can be said to be twice another.