JavaScript is a very weakly typed language. In other words it is very forgiving about how you use data types. It will try to figure it out on it's own. You can use single or double quotes, but you must end the string with the same quote mark that began it. If you enclose a single quote within double quotes you will be fine, if not you will get an error.
Permanent data is stored in a database.
Temporary data is stored in a variable. Variable names are case-sensitive and can't used certain reserved words or special characters. Variable names cannot begin with numbers. To use a variable you must first declare it. Loops for a specified number of times.