Variables store information. Well, at least that is all you need to know for now. If you think of a variable like a little box then it makes things somewhat easier :-). Variables are defined in the following way:
This may look a little bit odd, and you wont know much about scope until a little later on. Dont get scared! Trust me its easier than it looks. Heres a nice example of a variable for the class we defined previously.
This is a public integer called helloWorld. Its scope it public (But you dont need to know what this means yet) and its an integer (You dont need to know what this means yet either...).
These variables are known as Class Variables because they can be seen by all the different methods in your Class. There are other variables which you use in methods and I call those "Local" variables or "Temporary" variables, mainly because I cannot remember the proper name. These are used inside of methods and cannot be seen outside of them (Hence the "temporary" name).
One final thing to note is that Variable definitions are followed by a semicolon. Like with the curly brackets, the semicolon is something that you'll see a lot more of later on.