"type" command is useful for typing keyboard key values into text box of software web application. you can also use it for selecting values of combo box.
In this example, First it will type text "firstname.lastname@example.org" into text field "name=email" of software web page and then it will click on button element "css=input[type="submit"]".
"typeAndWait" command will be useful when your typing completed, software web page start reloading. This command will wait for software application page to reload. If there is not page reload event on typing, then you have to use simple "type" command.