Enterprise Resource Planning (ERP), or sometimes an enterprise information system, is a system by which an enterprise (or other organization) manages and integrates all or most of its business areas, such as planning, inventory, purchasing, sales, marketing, finance, human resources, etc. Each organizational unit (department) typically needs its own application capable of meeting its needs. With ERP, each department gets its own application, but it is also an application that can communicate and share information with everyone else across the organization. ERP also means software that provides all this.

[Source: www.wikipedia.org]