You can think of email templates as form letters that can be customized for one-time use or saved as a new template. You might want to set up a standard template for rejection letters, invitations to come in for interviews, or requests for references, for example.
If you use a template as the basis for an email, but do not save it as a new template, any changes you made to the template will be sent to the recipient but will not be retained for future use. To keep a copy of what you send to each candidate, click Send a copy of this email to myself each time.