Continuous classes, or ranges of values, run from one point to
another, with no clear separations of values. An example is a
temperature range.
Discrete classes have clear separation of values. Discrete
classes are sets, or enumerations.
Boolean classes are either true or false. Boolean classes only
have two values, either true or false, on or off, yes or no. An
example is whether a checkbox is checked or unchecked.
