"Switch" function allows you to output a custom message depending on the user input. It simplifies some cases when you would use "If" conditions. It should be used if you have radio buttons, dropdown menus, or multiple lists and, on one hand, want to leave field values short and simple, and, on the other, hand want to output human-readable text depending on the user's choice. For example the "Switch" function can be used in email templates to allow a user to choose the department where email should be sent without storing the email on the form page.