Difference between variable and attribute ?
Ordinarily, anything that varies/changes over time is taken as variable. But not in Statistics. Colour of your hair may change over time. Is it a variable? No, not at all. Why? because this change cannot be numerically expressed. In Statistics, only that change of an object is taken as a variable which can be numerically expressed. For example, average height of the students of class 10th in the year 2005 is found to be (say) 5.6 compared to 5.5 in the previous year. Qualitative change, like a change in IQ level of the students of class 10th is called Attribute. A change in the attribute is only qualitatively expressed as good, excellent and outstanding. Qualitative changes can at best be ranked as 1, 2, 3 where 1 stands for outstanding, 2 stands for excellent and 3 stands for good.