A ERP is a software package which ensures the update in real time of the whole of information relative to the various functions of the company. This includes the sale, production, buying orders as well as the product and inventory control. This update is carried out by maintaining a bond with the other functions support (accountancy, MRH, etc). [Apics]
A ERP is a modular, skeletal, integrated and opened data-processing application, which aims federating and at optimizing the processes of business management by proposing a single reference frame and while being based on rules of management standards.