Ring groups are a feature in Voice over IP (VoIP) systems that allow a group of extensions to ring simultaneously when a call is made to the group's designated number. This feature is often used by businesses to ensure that calls are answered promptly and efficiently, even if the desired extension is busy or unavailable.

For example, a business with a customer service department may set up a ring group with the extensions of all the customer service representatives. When a customer calls the customer service number, the call will ring on all the extensions of the customer service representatives at the same time. The first representative to answer the call will handle the call, while the other representatives' phones will stop ringing. This helps to ensure that calls are answered promptly and efficiently, improving the customer experience.

Ring groups can be configured to ring extensions in a specific order, or to use a specific ring pattern for each extension. They can also be set up to send calls to voicemail if no one answers within a certain amount of time. This feature is useful for businesses that want to ensure that calls are answered promptly, while also giving employees the flexibility to handle calls as they are able.