WebRTC allows for real-time communications like voice and video directly in web browsers without plugins. While SIP is a signaling protocol used for controlling multimedia sessions in VoIP, WebRTC focuses on media and does not define its own signaling protocol. WebRTC needs a separate signaling server and protocol like SIP to fully operate call setup. This marginalizes SIP's importance somewhat by making communications more accessible to developers and embedding them directly into applications rather than separate services. However, WebRTC and SIP can also benefit each other when used together.