CC at the end of a letter stands for "Carbon Copy." It has evolved to indicate "copy provided." The letter is copied to three persons in the following example. It is used if a copy must be sent to someone other than the original recipient. If this was not done, then more than one copy might be sent, which could cause confusion or lead to theft. The carbon copy method of communication allows multiple copies of an email to be sent to different recipients. This is different from a reply all where all recipients are notified when only one recipient responds. When you send a message and type c or cc after the subject line, this will put that message on a separate sheet known as a carbon copy. The person who receives the message can read the new message without affecting their copy of the original message. They will also receive an email notification that there is a new message waiting for them. People use carbon copies when they want to send a copy of their message to another person but still keep it accessible to their main message. For example, if you were writing a letter to your friend and wanted to include your mom as well, you could do so by typing mc followed by the name of her email address. When your friend sends the letter to your mother through email, she will also receive a copy via email.