Using an enterprise service bus, companies can increase their flexibility and reuse of IT assets, with an architecture based on service-oriented architecture (SOA).
A service-oriented architecture (SOA) offers a means to define services, which represent repeatable business tasks such as "check customer account", using well-defined, standards-based interfaces.
An enterprise service bus (ESB) provides a connectivity infrastructure that you can use to integrate services within an SOA.
Taken together, SOA and the ESB help to reduce the number and complexity of interfaces, enabling you to focus on your core business issues rather than the complexity of your IT infrastructure.