What is a variable? Technically, it's a tiny section of your computer's memory that will hold any information you put there. While a game runs, it keeps track of where the information is stored, the value kept there, and the type of the value. However, for this chapter, all you need to know is how a variable works in a script. It's very simple.
What's usually in a mailbox, besides air? Well, usually there's nothing but occasionally there is something in it. Sometimes there's money (a paycheck), bills, a picture from aunt Mabel, a spider, and so on. The point is what's in a mailbox can vary. Therefore, let's call each mailbox a variable instead.
Using the picture of the country mailboxes, if I asked you to see what is in the mailbox, the first thing you'd ask is which one? If I said in the Smith mailbox, or the brown mailbox, or the round mailbox, you'd know exactly which mailbox to open to retrieve what is inside. Similarly, in scripts, you have to name your variables with a unique name. Then I can ask you what's in the variable named myNumber, or whatever cool name you might use.
As you write a script and make a variable, you are simply creating a placeholder or a substitute for the actual information you want to use. Look at the following simple math equation: 2 + 9 = 11
Simple enough. Now try the following equation: 11 + myNumber = ???
There is no answer to this yet. You can't add a number and a word. Going back to the mailbox analogy, write the number 9 on a piece of paper. Put it in the mailbox named myNumber. Now you can solve the equation. What's the value in myNumber? The value is 9. So now the equation looks normal: 11 + 9 = 20
The myNumber variable is nothing more than a named placeholder to store some data (information). So anywhere you would like the number 9 to appear in your script, just write myNumber, and the number 9 will be substituted.
Although this example might seem silly at first, variables can store all kinds of data that is much more complex than a simple number. This is just a simple example to show you how a variable works.