Telegraphy the sense of a system that can transmit arbitrary messages over arbitrary distances. Lines of signalling relay stations can send messages to any required distance, but all these systems are limited to one extent or another in the range of messages that they can send. A system like flag semaphore, with an alphabetic code, can certainly send any given message, but the system is designed for short-range communication between two persons. An engine order telegraph, used to send instructions from the bridge of a ship to the engine room, fails to meet both criteria; it has a limited distance and
Messages (Apple) send audio and video messages by holding down the record button. In group conversations, users can remove/add someone to a thread, name a thread, share their location in a thread, view all attachments, and turn on Do Not Disturb to not receive notifications from a specific thread. As a part of the new continuity feature, users can now use their iPhones as a relay to send and receive SMS and MMS messages on their Macs and iPads. In iOS 9, the app received a redesigned overlay when sending an audio clip, as well as seeing contact photos in list view