Morse Code was invented by Samuel Morse in the 1840s. It is a collection of dashes and dots which are in fact a language with its own way of expressing words and punctuation. Morse code was used as an international standard for maritime communication until 1999 when it was retired in favour of different communication technologies.
The most famous Morse Code sequence is "SOS" (dot-dot-dot, dash-dash-dash, dot-dot-dot). Officially adopted as a distress call in 1908, it replaced the older "CQD" because of its ease of use and recognition.