CALLWAITING
Call waiting
Call waiting, in telephony, is a feature on some telephone networks. If a calling party places a call to a called party which is otherwise engaged, and the called party has the call waiting feature enabled, the called party is able to suspend the current telephone call and switch to the new incoming call, and can then negotiate with the new or the current caller an appropriate time to ring back. Call waiting, then, alleviates the need to have more than one line for voice communications.The above text is a snippet from Wikipedia: Call waiting
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