Per capita ecological footprint (EF), or ecological footprint analysis (EFA), is a means of comparing consumption and lifestyles, and checking this against nature's ability to provide for this consumption.
This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (April 2016) (Learn how and when to remove this template message) A Product Requirements Document (PRD) is a document containing all the requirements to a certain product. It is written to allow people to understand what a product should do.
A function is described as a set of inputs, the behavior, and outputs (see also software). Functional requirements may be calculations, technical details, data manipulation and processing and other specific functionality that define what a system is supposed to accomplish. typical functional requirement will contain a unique name and number, a brief summary, and a rationale. This information is used to help the reader understand why the requirement is needed, and to track the requirement through the development of the system.