WebSockets enable two-way communication between an application on a user's computer and a server, allowing for real-time updates without the need for continuous requests. This is particularly useful for multi-user applications and voice/video interactions where clients must continually send and receive information in real time. In contrast, WebRTC is better suited for one-on-one use cases due to its peer-to-peer protocol, which enables direct communication between browsers without the need for a central server. While both technologies are used for real-time voice and video communication, their ideal use cases differ, with WebSockets being more efficient for situations involving multiple users but potentially affecting audio/video quality, and WebRTC being preferable for one-on-one interactions due to its efficiency in streaming.