In the sample script, notice how constant values are all snake case uppercase. That means all words are separated by underlines, and all letters are in the uppercase format.
Compare that to the variable naming convention of snake lowercase. Meaning all words are separated by underscores, and all letters are lowercase.
You are free to choose your naming conventions.
Just make sure that constant names look different than variable names.
This makes it easy for you to see which variable names are free to change and which constant variables are not open to change.
What’s the difference between a constant variable and a variable?
When it comes to small projects, you may find that their really is no difference between
the two. However, as a projet grows bigger, and the more people are working on the same
project, the more benefits their are to properly using the correct declaration type.
A constant variable is useful for showing through code that a value will never change.
A variable on the other hand lets you know that the value will change throughout the
lifetime of the program.
Visibly, a constant variable should look different than a variable.
It is recommended that you use upper case for constants while using lowercase for variables.
It is the visual difference that is key here, especially when debugging. The capital
constants make it easier to debug code.