RestComm Client for Web allows you to leverage the telecommunication features of RestComm. It offers a simple yet efficient JS API that you can use to add rich communications capabilities to your Web Apps.
Device is an abstraction of a communications device that can initiate/receive calls and send/receive messages. Connection represents a media connection between two parties. In order to get advantage of the event mechanism offered by RestComm Client you need to add callbacks to events that interest you such as incoming calls and messages.