Most systems integrate today through APIs or direct database connections. Enterprise services buses are becoming a more popular alternative to API when it comes to creating integrations. Events can easily be processed through ESB when they arrive or when the event happens. Today most UI based applications function based off trigger events; for example- when you click on a button, the code behind the click event of the button performs certain functionality and fires off a "next step" or "task". Take that same concept and apply it to the back end and you are able to perform functions when events fire off. We explain more below.