What are the differences between a class constant and a class variable in PHP?

Class constants and class variables in PHP have some fundamental differences. Constants are immutable, meaning their values cannot be changed after they are defined, while variables can be modified throughout the execution of a script. Additionally, constants are considered static and shared across all instances of the class, whereas variables can have different values for each instance of the class. Understanding these distinctions is crucial when deciding whether to use a constant or a variable based on the desired behavior and usage requirements. To know more, refer to: http://php.net/manual/en/language.oop5.constants.php, http://php.net/manual/en/language.oop5.visibility.php