controller parameters($params,$data,$request) explanation?

[worldmiros]

I think I understand the $request based on externalaccount, but can you explain $params and $data parameters, and how would I use it on the client and server side?

[tarasm]

When I edit an Account it will be a request (PATCH) to http://172.20.0.4/espo/releases/4.1....2891ba9c4bc501 with payload data "{"name":"Test"}".
So, the parameters (var_dump):

$params = array(3) {
  ["controller"]=>
  string(7) "Account"
  ["id"]=>
  string(17) "5772891ba9c4bc501"
  ["action"]=>
  string(5) "patch"
} 

$data = array(1) {
  ["name"]=>
  string(4) "Test"
} 

$request = object of Slim\Http\Request