1. What Is an alert?
The alert is a modal dialog that takes the focus away from the current window and forces the user to take action before performing other actions. It also prevents the user from accessing other parts of the page until the user performs the action presented in the dialog. For example, when the user clicks on the “Delete” button, an alert would be triggered asking the user, ‘Are you sure, you want to delete this?’ The user has to take action on this dialog.