In most browsers forms influence the page layout. They start on a new line, and have a blank line before and after. The default is a one line text box. The size depends on type of browser, and font settings. With these tags you now have a complete and valid html form.
Most forms consist of multiple input fields.
To discern between them you give the fields a name. This also makes it possible to work with the data the form produces. You can name it anything you like, just beware of exotic characters. Simple alphanumeric characters should be fine. What you have now is a complete form.