Well thats quite easy, you should see variables as little spaces in which you can store information, and withdraw again so they won't get lost.
To get to the variable editor, you first need to go to the trigger editor, and then press "Ctrl+B" (thats the short cut to the variable editor).
A new window will open.
Click on the green button or press "Ctrl+N" (which is the shortcut for making a new variable), to make a new variable.
A new window will enfold itself with the following 4 things.
Variable name:
Variable type:
array:
Initial value:
#Variable name
The variable name could be anything, but I suggest using a name that represent what it will do.
#Variable type
Next thing up is the type of the variable, the type of the variable is very important, since it will decide what you can store in it, if you need to store a number in you could use "Integer" or "Real", but if you need to store a unit in there, than you could use "Unit" as variable type.
Most types are self explanetory, even more the onces that you will be needing the most.
#array
The array function is a very handy thing, but its a tad complicated as well, an array means a widthspan, which actually means that you can have more variables in one variable, arrays are oftenly used when you need an "Integer A" as action in a trigger, but its suitable for other occasion as well, but I would suggest learning more about variables first, and then arrays and how they work will come to itself.
#Initial value
The initial value is not to real big importance, atleast I rarely use it, since you can easily set it at the start of the game yourself with a trigger.
Once you created a variable you can start using it, store information in it, by using the the action:
"Set variable"
And withdraw it with other actions when you need it again.
A few notes are
* These are global variables, which means you can't create 2 variables with the same name.
* You do not need to reset the variable when you want to use it again, you can just copy your new data over the old one.
Germ maker2
Events
Unit - A unit Dies
Conditions
(Unit-type of (Triggering unit)) Equal to Germ
Actions
Wait 5.00 seconds
