A sag is a momentary low voltage. A spike is a momentary high voltage. A fault is a momentary power out and a brownout is a prolonged power supply that is below normal voltage.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-
Hill/Osborne, 2002, chapter 6: Physical security (page 299).

Life safety, or protecting the health and safety of everyone in the facility is the first priority in an emergency or disaster. Evacuation routes, assembly areas, and accounting for personnel (head counts and last-known locations) are the most important function of emergency procedures, before anything else. Once all personnel have been accounted for and emergency teams have arrived to prevent further damage or hazard, family members should be notified of the status of the event. Providing restoration and recovery, and implementing alternative production methods also comes later. Source: Emergency Management Guide for Business and Industry, Federal Emergency Management Agency, August, 1998.

Identification is a means to verify who you are. Authentication is what you are authorized to perform, access, or do. User identification enables accountability. It enables you to trace activities to individual users that may be held responsible for their actions. Identification usually takes the form of Logon ID or User ID. Some of the Logon ID characteristics are: they must be unique, not shared, and usually non descriptive of job function

TCP is a connection-orientated protocol.