req params vs req query vs req body code example

Example 1: difference between req.query and req.params

req.params contains route parameters
(in the path portion of the URL),
and req.query contains the URL query parameters
(after the ? in the URL).

You can also use req.param(name) to look up a parameter in both places
(as well as req.body),
but this method is now deprecated.

Example 2: req.params vs req.body

//this is just for me lol
	* req.user: object make by passport.js added to req that include a username and user id
	* req.params: from path segments of URL that match a route definition parameter 
    	* /song/:id
	* req.body: hold parameters sent by post request (like form data)