Just as values such as 3.6, or 90000 have a number type and values such as "Hello world!" or "5 plus five is 10" have a string type, there are values that have a Boolean type. There are only two Boolean type values and these are:
An example of a property that takes Boolean values is the picture's Visibility property. The Visibility property is set to TRUE by default (since the picture should be visible by default). Setting the property to FALSE makes the picture disappear.
Note that Boolean values must be written in upper case, otherwise they will be assumed to be variable names.