Short for blind carbon copy, a copy of an e-mail message sent to a recipient without the recipient's address appearing in the message. Most e-mail clients include two fields labeled cc and bcc. When you enter addresses in the cc field, the message is copied to those addresses and the cc addresses appear at the top of the e-mail message. When you enter addresses in the bcc field, however, the addresses do not appear in the message. This is useful if you want to copy a message to many people without each of them seeing who the other recipients are.