Unfortunately I can't see the initial difference between *** and *** accounts.
But a User is: A user is someone who uses a certain computer or network service. Ie. someone with a facebook account, is a facebook user. A user has a their own user account or username attributed to them.
And an Email defined as: Short for electronic mail, e-mail or email is information stored on a computer that is exchanged between two users over telecommunications. More plainly, e-mail is a message that may contain text, files, images, or other attachments sent through a network to a specified individual or group of individuals.