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.
The term requirement has been in use in the software engineering community since at least the 1960s. According to the Business Analysis Body of Knowledge (BABOK), a requirement is: A condition or capability needed by a stakeholder to solve a problem or achieve an objective.