RAM

Random-access memory (RAM /ræm/) is a form of computer data storage. A random-access memory device allows data items to be read and written in approximately the same amount of time, regardless of the order in which data items are accessed.^[1] In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement delays.

MasterCard

 MasterCard Incorporated (NYSE: MA) or MasterCard Worldwide is an American multinational financial services corporation headquartered in the MasterCard International Global Headquarters, Purchase, New York, United States,^[1] in Westchester County. The Global Operations Headquarters is located in O'Fallon, Missouri, United States, a suburb of Saint Louis, Missouri. Throughout the world, its principal business is to process payments between the banks of merchants and the card issuing banks or credit unions of the purchasers who use the "MasterCard" brand debit and credit cards to make purchases. MasterCard Worldwide has been a publicly traded company since 2006. Prior to its initial public offering, MasterCard Worldwide was a cooperative owned by the 25,000+ financial institutions that issue its branded cards.

Visa Card

 VISA stands for Visa International Settlement Association. It is an American multinational financial services corporation headquartered in Foster City, California, United States.[3] It facilitates electronic funds transfers throughout the world, most commonly through Visa-branded credit cards and debit cards.[4] Visa does not issue cards, extend credit or set rates and fees for consumers; rather, Visa provides financial institutions with Visa-branded payment products that they then use to offer credit, debit, prepaid and cash-access programs to their customers. In 2008, according to The Nilson Report, Visa held a 38.3% market share of the credit card marketplace and 60.7% of the debit card marketplace in the United States.[5] In 2009, Visa’s global network (known as VisaNet) processed 62 billion transactions with a total volume of $4.4 trillion.[6][7]

Audit trail

 An audit trail (also called audit log) is a security-relevant chronological record, set of records, and/or destination and source of records that provide documentary evidence of the sequence of activities that have affected at any time a specific operation, procedure, or event.^[1][2] Audit records typically result from activities such as financial transactions,^[3] scientific research and health care data transactions,^[4] or communications by individual people, systems, accounts, or other entities.

The process that creates an audit trail is typically required to always run in a privileged mode, so it can access and supervise all actions from all users; a normal user should not be allowed to stop/change it. Furthermore, for the same reason, trail file or database table with a trail should not be accessible to normal users. Another way of handling this issue is through the use of a role-based security model in the software.^[5] The software can operate with the closed-looped controls, or as a 'closed system,' as required by many companies when using audit trail functionality.