Numerical variables, also known as quantitative variables, are characteristics that can be measured and expressed in numbers. They represent a notion of magnitude and can be further classified into two main types: discrete and continuous. Discrete variables have countable values, such as the number of students in a class or the number of goals scored in a game. In contrast, continuous variables can take on an infinite number of values within a given range, such as height, weight, or temperature. Understanding numerical variables is essential for statistical analysis and data interpretation, as they provide meaningful insights into the data being studied.