A Business Impact Analysis (BIA) is an assessment of an organization's
business functions to develop an understanding of their criticality, recovery time objectives,
and resources needed.
By going through a Business Impact Analysis, the organization will gain a common
understanding of functions that are critical to its survival.
A risk assessment is an evaluation of the exposures present in an organization's external
and internal environments.
A Business Assessment generally include Business Analysis as a discipline and it has
heavy overlap with requirements analysis sometimes also called requirements engineering,
but focuses on identifying the changes to an organization that are required for it to achieve
strategic goals. These changes include changes to strategies, structures, policies,
processes, and information systems.
A disaster recovery plan is the comprehensive statement of consistent actions to be taken
before, during and after a disruptive event that causes a significant loss of information
systems resources.
Source: BARNES, James C. & ROTHSTEIN, Philip J., A Guide to Business Continuity
Planning, John Wiley & Sons, 2001 (page 57).

Section: Access Control
Explanation/Reference:
In response to an access-request from a client, a RADIUS server returns one of three authentication responses: access-accept, access-reject, or access-challenge, the latter being a request for additional authentication information such as a one-time password from a token or a callback identifier.
Source: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 2, 2001, CRC Press, NY, page 36.

Explanation/Reference:
The most likely source of exposure is from the uninformed, accidental or unknowing person, although the greatest impact may be from those with malicious or fraudulent intent.
Source: Information Systems Audit and Control Association, Certified Information Systems Auditor 2002 review manual, Chapter 4: Protection of Information Assets (page 192).

The Differential Backup Method is additive because the time and tape space required for each night's backup grows during the week as it copies the day's changed files and the previous days' changed files up to the last full backup. Archive Bits
Unless you've done a lot of backups in your time you've probably never heard of an Archive Bit. An archive bit is, essentially, a tag that is attached to every file. In actuality, it is a binary digit that is set on or off in the file, but that's crummy technical jargon that doesn't really tell us anything. For the sake of our discussion, just think of it as the flag on a mail box. If the flag is up, it means the file has been changed. If it's down, then the file is unchanged.
Archive bits let the backup software know what needs to be backed up. The differential and incremental backup types rely on the archive bit to direct them. Backup Types
Full or Normal The "Full" or "normal" backup type is the most standard. This is the backup type that you would use if you wanted to backup every file in a given folder or drive. It backs up everything you direct it to regardless of what the archive bit says. It also resets all archive bits (puts the flags down). Most backup software, including the built-in Windows backup software, lets you select down to the individual file that you want backed up. You can also choose to backup things like the "system state".
Incremental When you schedule an incremental backup, you are in essence instructing the software to only backup files that have been changed, or files that have their flag up. After the incremental backup of that file has occured, that flag will go back down. If you perform a normal backup on Monday, then an incremental backup on Wednesday, the only files that will be backed up are those that have changed since Monday. If on Thursday someone deletes a file by accident, in order to get it back you will have to restore the full backup from Monday, followed by the Incremental backup from Wednesday.
Differential Differential backups are similar to incremental backups in that they only backup files with their archive bit, or flag, up. However, when a differential backup occurs it does not reset those archive bits which means, if the following day, another differential backup occurs, it will back up that file again regardless of whether that file has been changed or not.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69.
And: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 9: Disaster Recovery and Business continuity (pages 617-619). And: http://www.brighthub.com/computing/windows-platform/articles/24531.aspx

Section: Risk, Response and Recovery
Explanation/Reference:
A data backup is the first step in contingency planning.
Without data, there is nothing to process. "No backup, no recovery".
Backup for hardware should be taken care of next.
Formal arrangements must be made for alternate processing capability in case the need should arise.
Operating systems and application software should be taken care of afterwards.
Source: VALLABHANENI, S. Rao, CISSP Examination Textbooks, Volume 2: Practice, SRV Professional Publications, 2002, Chapter 8, Business Continuity Planning & Disaster Recovery Planning (page 506).