What is the difference between these two methods of establishing a variable?
JavaSript
var img = $('#redImage');
jQuery
var $img = $('#redImage');
What is the difference between these two methods of establishing a variable?
JavaSript
var img = $('#redImage');
jQuery
var $img = $('#redImage');
 
    
    The have different names (one of them starts with a $ sign, the other does not). That is all. The $ has no special meaning, it is just a character.
Some people use variables starting with a $ as a hint that the variable is expected to have a jQuery object assigned to it. This is much like the Hungarian Notation style of prefixing variable names with letters to indicate the type.
 
    
    $ in var $img is just a naming convention to signify that the variable is a jQuery object
While Doing this -
var img = $('#redImage');
var $img = $('#redImage');
You actually defined two variables with different name -  img and $img
 
    
    One creates a variable named img and the other creates a variable name $img ... The dollar sign is a perfectly valid character in a variable name.