What is "enterprise service bus"

n. (context computing English) A layer in the abstract architecture of the message system of an organization.

An enterprise service bus (ESB) is a software architecture model used for designing and implementing communication between mutually interacting software applications in a service-oriented architecture (SOA). As a software architectural model for distributed computing, it is a specialty variant of the more general client-server model and promotes agility and flexibility with regard to communication between applications. Its primary use is in enterprise application integration (EAI) of heterogeneous and complex landscapes.