Final answer:
A variable is a characteristic or measurement that can be quantitative or categorical. Quantitative variables have numerical values with equal units, while categorical variables place individuals or things into categories.
Step-by-step explanation:
A variable is a characteristic or measurement that can be determined for each member of a population. In statistics, a variable can be quantitative or categorical. A quantitative variable is a variable that can take on numerical values and has equal units, such as weight or time. A categorical variable is a variable that places individuals or things into categories, such as party affiliation.