Variables have a lot of uses, they are great for changing values like a timer, or durability. They can also be used repeatedly throughout your script, or even be saved for later. You can even use an object variable to reference another object. Remember you can always get a one time use value input from the Values tab.
VALUES precedes this tutorial
Once a variable has been created, you can set the default initial value, which can also be changed from an individual object’s property panel, allowing for unique variations.
If you want to create a list, toggle the list option on when creating a variable. This adds brackets around the variable type icon to indicate that it is a list. Please note, you will need to use the List codeblocks found on your operators tab to add to the list and interact with it.