The idea of enterprise resource planning (ERP) is to gather unique data in real time about all managerial activities happening in a company.
ERP can be defined as the set of cross organization integrated applications (software products) that covers the business cycle of a firm (including sales, production, human resources or financial accounting).
It aims at helping companies to better plan their activity and use their inputs and outputs more effectively.
They belong to the group of integrated systems aiming at connecting and synchronizing all the activities of all different departments of an enterprise.
ERP software and business software are not equivalent. Many businesses use some kind of software for their activities (in accounting: AccountEdgePro 2012). ERP solutions make all of the latter unnecessary.
An example, a very good friend just told me that it is like the software of a hosting, a website or a blog: you may use joomla, wordpress or blogspot. All of them come with special characteristics (widgets, themes, CSS, etc.) to help your business or yourself do your activity. Therefore it is important to choose one with all the «functions», that is to say, one which has already parameterised all your needs so that you manage all your transactional processes (now intregated and automatised thanks to this IT tool).
Maybe this explanation is not enough… Then, just a few minutes of this video,trust it, one can get an excellent idea about what ERP is:
If you never have experienced what ERP is, find a free demo by Openbravo, an open software ERP
Kleof site: http://www.facebook.com/pages/Kleofs-Social-Place/153717744696586
ERP, an anotated bibliography: http://profesores.ie.edu/jmesteves/cais2001.pdf