Message in its most general meaning is the object of communication. Depending on the context, the term may apply to both the information contents and its actual presentation.

In the communications discipline, a message is information which is sent from a source to a receiver. Some common definitions include:

• Any thought or idea expressed briefly in a plain or secret language, prepared in a form suitable for transmission by any means of communication.
• An arbitrary amount of information whose beginning and end are defined or implied.
• Record information , a stream of data expressed in plain or encrypted language (notation) and prepared in a format specified for intended transmission by a telecommunications system.

In computing, under certain object-oriented programming languages such as Smalltalk and Objective-C, a message is an instruction to an object to perform some task. A message is similar to a member function, however in certain run-time environments such as Objective-C, messages can be forwarded if an object does not recognize — respond to — a certain message.

See also: instant messaging

History of messaging

• Smoke signals - Ancient (short distance only)
• Wind-power shipping (hence the name) "In 1800, it took 2 years to send a message from London to Calcutta. You wrote a physical letter and entrusted it to a wind-powered ship that sailed down the western coasts of Europe and Africa, around the Cape of Good Hope, back up the eastern coast of Africa, across the Arabian Sea, etc. -- with, presumably, stops in just about every port (yes, they had multi-hop message transports back then)." [1]
• Semaphore - Limited use
• Telegraph - (late 19th century)
• Telephone - (late 19th century-early 20th century)
• Steamshipping "By 1914, it took 1 month to send a message from London to Calcutta. The Suez Canal had opened, and steamships powered their way through the Mediterranean to the Red Sea, and thence to India. Big improvement."[1]
• Radio, (early 20th century)
• Television - (mid 20th century)
• Airmail (1950s or 1960s?) ~ 1 week.
• Overnight mail - became popular and affordable in the 1980s, made the international messaging only two days.
• Electronic mail (~1994) - delivery times of 10 minutes, based on number of hops, frequency of manual retrieval, etc.
• Instant messaging - Message travels at average 100 milliseconds, almost always less than a second.

References

1. "Brief history" section adapted from Peter Saint-Andre "The Need For Speed"
2. Department of Defense Dictionary of Military and Associated Terms
3. Federal Standard 1037C