‘Cc’ stands for Carbon copy. It sends the same email to a specified set of users. Here every user can see all the emails IDs to which the mail was sent to.
‘Bcc’ stands for Blind carbon copy. It sends the same email to a specified set of users. Here none of the users can see the emails IDs to which the mail has also been sent to.
Click on the links only if the addresses of the users you wish to send to, already exist in your address book. Otherwise, you can manually enter the addresses. With the new Rediffmail, you have the option to add/hide the BCC tab as per requirement by clicking on ‘Add Bcc/Remove Bcc’.