EIS is an acronym for enterprise information system. An enterprise information system is the set of applications that comprise an enterprise's system for handling company-wide information. These applications provide an information infrastructure for an enterprise. An enterprise information system offers a well-defined set of services to its clients. These services are exposed to clients as local or remote interfaces. Examples of enterprise information systems include: enterprise resource planning systems, mainframe transaction processing systems, and legacy database systems. J2EETM Connector Architecture.