Students will not receive any notifications if their application to a job has been declined on Handshake, unless you have opted to set up Automatic Applicant Status Messaging Preferences. In this case, a screen will appear for you to first approve the message that is sent, before the notification is submitted. Read more on this feature here: About Setting Up Automatic Applicant Status Messaging Preferences
If the applicant is part of an Interview Schedule and is declined, they will receive a notification that they have been declined.
Students will be able to log into their account, view their applications, and see that their status has changed from Pending to Declined.