When creating an e-mail you can send a copy of it to someone else using the CC address field. CC standing for Carbon Copy or Circulate Copy is a hold-over from typewriters and the typing pools of the 1960s.
If the email is to one or two people, friends who know each other well, enter your name in the To field and every other address in the CC field.
If however you are mailing multiple users who do not know each other well, virtual strangers to one another, use the BCC or Blind Carbon Copy option. This can also be referred to as Blind Circulate Copy.
The message will still be delivered to every intended recipient, but the e-mail address of everyone will not be transmitted along with it, protecting each person's right to privacy.