Discrete vs. Continuous Variables

Discrete variables have a finite or countable number of values associated with them. For example, any variable whose description starts out with "The number of..." is a discrete variable.

Continuous Variables, on the other hand can assume any real value in some interval. For example, a certain species of fish might measure anywhere between 10.6 inches to 26.3 inches. That said, don't worry if you never actually see a fish of length 15.32975612386561 inches. We always have to round these types of variables to some more reasonable number of decimal places given the limits of our measuring devices.