Any information belonging to a cardholder that needs to be protected (because of identity-theft concerns, or privacy requirements, etc). The most important examples of this are information taken the magnetic stripe of a card, or the card number, plus things like card expiration dates, or cardholder name,
Sharing information in a secure way, so that attackers can neither read it nor change it.
Destroying or wiping media so that the information on it cannot be read or mis-used by outsiders. At current media prices, itt is relatively cheap to do this properly by physically destroying the thing holding the data (for example, by breaking the CD in half).
Process for deleting sensitive data from a file, device, or system; or for scrambling data so that it is useless if accessed.
Hardware or software that connects two or more networks, and allows computers to talk to each other.
The 'boss' account on a computer: the account that has permission to do anything possible to the computer.
Official, documented rules about who should do what in the case of an emergency or particular event. These need to be prepared in advance, with everyone involved knowing in advance what their responsibilities are.
Controlling a computer from a remote location. This is usually done to fix problems or to change settings.
Any part of a network that outsiders can connect to from their computers. Examples include any web server that outsiders can look at pages on.
Any computer network or communications system that is intended for use by the general public. The most obvious examples are the Internet, Web, GPRS, and GSM. Communications over a public network cannnot be assumed to be private, and therefore require the use of encryption.