As with any type of application that takes user input, you'll need a way to verify that the inputs are actually correct. One easy way to present a friendly message to your users is by using <b>UIAlertController</b> to present a small warning box if you've detected invalid form entries. This process of checking user fields is typically referred to as <b>Form Validation</b>. Let's see this in action by introducing a birthday field for out <b>Employees</b>