Q:

What is "$" in jquery framework?

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What is the $ in jQuery? 

We know that $ is an alias of jQuery, while using jQuery javascript framework.
But internally what $ is ?
I mean whether it is an object, function or other thing?

A:

$ is a function object in jQuery.  It can take a number of different types of parameters or methods.  That's why you will see things like: 
$("#content")

In that use, it's just a function - identical to:
jQuery("#content")

In this example, it returns an object that contains both the collection of DOM items matching the passed in CSS string and has a whole bunch of methods that let you operate on that collection of items it returned such as:
var html = $("#content").html()

to get the innerHTML of that DOM object.
It is usually used like a function $(params), but can also has methods as an object $.get().
But, most of all $ is just a symbol for a function object that also has methods.  It could be called foo or anything else so it's not anything unusual in Javascript.

