what is the difference between req.query and req.data nodejs code example

Example: 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.