What is the difference: this and this.root

1

i tried these two code, and i found that when i deleted the imports lines and this keyword is still works.


import flash.display.*;
import flash.text.TextField;
var myText:TextField = new TextField();
myText.text = "Buenos dias.";
this.addChild(myText);

also here, this.root: why it is here?


var myTextField:TextField = new TextField();
myTextField.text = "hello";
this.root.addChild(myTextField);