The definition of an Electronic Flight Bag (EFB), according to the FAA's Advisory Circular (AC No. 120-76A), is an electronic display system intended primarily for cockpit / flightdeck or cabin use. EFB devices can display a variety of aviation data or perform basic calculations (e.g., performance data, fuel calculations,etc.). In the past, some of these functions were traditionally accomplished using paper references or were based on data provided to the flight crew by an airline's "flight dispatch" function. In short, an EFB is an electronic information management device that helps flight crews perform flight management tasks more easily and efficiently, in a less-paper environment.

As they are designed to replace the heavy and cumbersome traditional pilot flight bag, EFB systems are relatively small and light (only a few pounds at most). They typically consist of a screen and a control unit that may be installed, mounted or contained in one sole portable unit. EFBs can electronically store and retrieve documents required for flight operations, such as the General Operations Manual (GOM), Minimum Equipment Lists (MEL), Flight Crew Operating Manual (FCOM), and other controlled documents/data. One of the major motivators for using an EFB is to reduce or eliminate the need for paper and other reference materials in the cockpit.

Aviation Authorities Guidance Material

FAA AC-120-76A: "Guidelines For The Certification, Airworthiness, And Operational Approval Of Electronic Flight Bag Computing Devices".

JAA / EASA TGL36: Approval of Electronic Flight Bags"