SAP stands for Systems, Applications and Products. It uses the concept of modules ("individual programs that can be purchased, installed, and run separately, but that all extract data from the common database").
SAP AG, the company that provides the enterprise resource planning solution has upgraded the package and launched it as SAP ECC 6.0 in 2005. ECC stands for Enterprise Central Component. The purpose of positioning it as ECC is to enable SAP to build and develop an environment of other products that can function upon the foundation of the central component.