Variables
<script>
	var id;
	var name;
</script>

Variables
<script>
	var id, name;
</script>

Variables
<script>
	var id = 113;
	var name;
	name = “Ned”
</script>

Variables
Global Scope – variables defined anywhere in the JavaScript code. These variables are accessible to all functions that have no duplicate identifier names.
Function Scope – variables declared within a function. These variables are only visible within its function.
Block Scope – variables declared within a block (i.e., { }). These variables are only visible within its block. New feature as of ES6 (2015) & onwards. 

Variables... example
<script>
	var myVar = "global"; // global scope
	function sample() {
		var myVar = "func"; //function scope
		document.write(myVar);
		if (myVar == "func")
		{
			let myVar = "block"; // block scope
			document.write("block" + myVar);
			var myVar2 = "func"; // STILL function scope		}
	}
</script>