Discrete variables are types of data that can take on a countable number of distinct values. These values are often whole numbers, such as the number of students in a classroom or the number of cars in a parking lot. Discrete variables cannot be divided into smaller parts, meaning you cannot have half a student or a fraction of a car. Examples of discrete variables include gender, number of pets, and test scores. In contrast to continuous variables, which can take on any value within a range, discrete variables are limited to specific, separate values. This makes them useful for counting and categorizing data.