(Enterprise Application Integration) Refers to various techniques used to share data and business processes in large enterprises. When companies acquire another organization, disparate information systems have to be made to work together. Even within a company, many systems have been developed separately and run in isolation, as well as on different platforms. EAI allows multiple systems be merged and monitored, and business intelligence can be gleaned across the entire enterprise.

EAI software may function as a central distribution hub, providing data and command conversions where necessary between applications. It is also a major component of a business process management suite (BPMS). See application integration and BPM.

EAI, EII and ETL
EAI often entails conversion from one format to another and differs from EII (enterprise information integration), which aggregates current information from disparate sources. EAI also differs from ETL (extract, transform, load), which migrates data from one database into another. See EII and ETL.